Armor Class 14 (natural armor), 11 while prone)
Hit Points 39 (6d10 + 6)
Speed 30 ft., burrow 10 ft.

Saving Throws 
Skills 
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 60 ft., tremorsense 60 ft., passive Perception 11
Languages --
Challenge 2 (450 XP)

Actions

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) slashing damage plus 3 (1d6) acid damage. If the target is a Large or smaller creature, it is grappled (escape DC 13). Until this grapple ends, the ankheg can bite only the grappled creature and has advantage on attack rolls to do so.

Acid Spray (Recharge 6). The ankheg spits acid in a line that is 30 feet long and 5 feet wide, provided that it has no creature grappled. Each creature in that line must make a DC 13 Dexterity saving throw, taking 10 (3d6) acid damage on a failed save, or half as much damage on a successful one.

Armor Class 13 (natural armor)
Hit Points 44 (8d8 + 8)
Speed 30 ft., climb 30 ft.

Saving Throws 
Skills Perception +3, Stealth +4, Survival +3
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 60 ft., passive Perception 13
Languages --
Challenge 2 (450 XP)

Spider Climb. The ettercap can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Web Sense. While in contact with a web, the ettercap knows the exact location of any other creature in contact with the same web.

Web Walker. The ettercap ignores movement restrictions caused by webbing.

Actions

Multiattack. The ettercap makes two attacks: one with its bite and one with its claws.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 6 (1d8 + 2) piercing damage plus 4 (1d8) poison damage. The target must succeed on a DC 11 Constitution saving throw or be poisoned for 1 minute. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) slashing damage.

Web (Recharge 5–6). Ranged Weapon Attack: +4 to hit, range 30/60 ft., one Large or smaller creature. Hit: The creature is restrained by webbing. As an action, the restrained creature can make a DC 11 Strength check, escaping from the webbing on a success. The effect also ends if the webbing is destroyed. The webbing has AC 10, 5 hit points, vulnerability to fire damage, and immunity to bludgeoning, poison, and psychic damage.

Armor Class 19 (natural armor)
Hit Points 123 (13d10 + 52)
Speed 30 ft., climb 30 ft.

Saving Throws 
Skills Perception +5, Stealth +9
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 120 ft., passive Perception 15
Languages Elvish, Undercommon
Challenge 6 (2300 XP)

Fey Ancestry. The drider has advantage on saving throws against being charmed, and magic can’t put the drider to sleep.

Innate Spellcasting. The drider’s innate spellcasting ability is Wisdom (spell save DC 13). The drider can innately cast the following spells, requiring no material components: At will: ““ 1/day each: ““, ““

Spider Climb. The drider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Sunlight Sensitivity. While in sunlight, the drider has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Web Walker. The drider ignores movement restrictions caused by webbing.

Actions

Multiattack. The drider makes three attacks, either with its longsword or its longbow. It can replace one of those attacks with a bite attack.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 2 (1d4) piercing damage plus 9 (2d8) poison damage.

Longsword. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage, or 8 (1d10 + 3) slashing damage if used with two hands.

Longbow. Ranged Weapon Attack: +6 to hit, range 150/600 ft., one target. Hit: 7 (1d8 + 3) piercing damage plus 4 (1d8) poison damage.

Armor Class 11
Hit Points 22 (5d6 + 5)
Speed 10 ft., fly 30 ft.

Saving Throws 
Skills Stealth +3
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses blindsight 60 ft., passive Perception 10
Languages --
Challenge 44928 (100 XP)

Echolocation. The darkmantle can’t use its blindsight while deafened.

False Appearance. While the darkmantle remains motionless, it is indistinguishable from a cave formation such as a stalactite or stalagmite.

Actions

Crush. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 6 (1d6 + 3) bludgeoning damage, and the darkmantle attaches to the target. If the target is Medium or smaller and the darkmantle has advantage on the attack roll, it attaches by engulfing the target’s head, and the target is also blinded and unable to breathe while the darkmantle is attached in this way. While attached to the target, the darkmantle can attack no other creature except the target but has advantage on its attack rolls. The darkmantle’s speed also becomes 0, it can’t benefit from any bonus to its speed, and it moves with the target. A creature can detach the darkmantle by making a successful DC 13 Strength check as an action. On its turn, the darkmantle can detach itself from the target by using 5 feet of movement.

Darkness Aura (1/Day). A 15-foot radius of magical darkness extends out from the darkmantle, moves with it, and spreads around corners. The darkness lasts as long as the darkmantle maintains concentration, up to 10 minutes (as if concentrating on a spell). Darkvision can’t penetrate this darkness, and no natural light can illuminate it. If any of the darkness overlaps with an area of light created by a spell of 2nd level or lower, the spell creating the light is dispelled.

Armor Class 12
Hit Points 39 (6d8 + 12)
Speed 40 ft.

Saving Throws
Skills Perception +5, Stealth +4
Damage Resistances
Damage Immunities
Condition Immunities
Senses darkvision 120 ft., passive Perception 15
Languages --
Challenge 1 (200 XP)

Two-Headed. The dog has advantage on Wisdom (Perception) checks and on saving throws against being blinded, charmed, deafened, frightened, stunned, or knocked unconscious.

Actions

Multiattack. The dog makes two bite attacks.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage. If the target is a creature, it must succeed on a DC 12 Constitution saving throw against disease or become poisoned until the disease is cured. Every 24 hours that elapse, the creature must repeat the saving throw, reducing its hit point maximum by 5 (1d10) on a failure. This reduction lasts until the disease is cured. The creature dies if the disease reduces its hit point maximum to 0. A death dog is an ugly two-headed hound that roams plains, and deserts. Hate burns in a death dog’s heart, and a taste for humanoid flesh drives it to attack travelers and explorers. Death dog saliva carries a foul disease that causes a victim’s flesh to slowly rot off the bone.

Armor Class 14
Hit Points 52 (8d8 + 16)
Speed 30 ft.

Saving Throws 
Skills Deception +6, Insight +3
Damage Resistances 
Damage Immunities 
Condition Immunities charmed
Senses darkvision 60 ft., passive Perception 11
Languages Common
Challenge 3 (700 XP)

Shapechanger. The doppelganger can use its action to polymorph into a Small or Medium humanoid it has seen, or back into its true form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.

Ambusher. The doppelganger has advantage on attack rolls against any creature it has surprised.

Surprise Attack. If the doppelganger surprises a creature and hits it with an attack during the first round of combat, the target takes an extra 10 (3d6) damage from the attack.

Actions

Multiattack. The doppelganger makes two melee attacks.

Slam. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage.

Read Thoughts. The doppelganger magically reads the surface thoughts of one creature within 60 feet of it. The effect can penetrate barriers, but 3 feet of wood or dirt, 2 feet of stone, 2 inches of metal, or a thin sheet of lead blocks it. While the target is in range, the doppelganger can continue reading its thoughts, as long as the doppelganger’s concentration isn’t broken (as if concentrating on a spell). While reading the target’s mind, the doppelganger has advantage on Wisdom (Insight) and Charisma (Deception, Intimidation, and Persuasion) checks against the target.

Armor Class 12
Hit Points 45 (6d10 + 12)
Speed 50 ft.

Saving Throws
Skills Athletics +6, Perception +3, Survival +3
Damage Resistances
Damage Immunities
Condition Immunities
Senses passive Perception 13
Languages Elvish, Sylvan
Challenge 2 (450 XP)

Charge. If the centaur moves at least 30 feet straight toward a target and then hits it with a pike attack on the same turn, the target takes an extra 10 (3d6) piercing damage.

Actions

Multiattack. The centaur makes two attacks: one with its pike and one with its hooves or two with its longbow.

Pike. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 9 (1d10 + 4) piercing damage.

Hooves. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.

Longbow. Ranged Weapon Attack: +4 to hit, range 150/600 ft., one target. Hit: 6 (1d8 + 2) piercing damage.

Armor Class 14 (natural armor)
Hit Points 114 (12d10 + 48)
Speed 30 ft., fly 60 ft.

Saving Throws 
Skills Perception +8
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 60 ft., passive Perception 18
Languages understands Draconic but can't speak
Challenge 6 (2300 XP)

Actions

Multiattack. The chimera makes three attacks: one with its bite, one with its horns, and one with its claws. When its fire breath is available, it can use the breath in place of its bite or horns.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage.

Horns. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 10 (1d12 + 4) bludgeoning damage.

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.

Fire Breath (Recharge 5–6). The dragon head exhales fire in a 15-foot cone. Each creature in that area must make a DC 15 Dexterity saving throw, taking 31 (7d8) fire damage on a failed save, or half as much damage on a successful one.

Armor Class 11
Hit Points 27 (6d6 + 6)
Speed 20 ft., fly 40 ft.

Saving Throws
Skills
Damage Resistances
Damage Immunities
Condition Immunities
Senses darkvision 60 ft., passive Perception 11
Languages --
Challenge 44928 (100 XP)

Actions

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: 3 (1d4 + 1) piercing damage, and the target must succeed on a DC 11 Constitution saving throw against being magically petrified. On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified for 24 hours.

Armor Class 17 (natural armor)
Hit Points 94 (9d10 + 45)
Speed 40 ft., burrow 40 ft.

Saving Throws 
Skills Perception +6
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 60 ft., tremorsense 60 ft., passive Perception 16
Languages --
Challenge 5 (1800 XP)

Standing Leap. The bulette’s long jump is up to 30 feet and its high jump is up to 15 feet, with or without a running start.

Actions

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 30 (4d12 + 4) piercing damage.

Deadly Leap. If the bulette jumps at least 15 feet as part of its movement, it can then use this action to land on its feet in a space that contains one or more other creatures. Each of those creatures must succeed on a DC 16 Strength or Dexterity saving throw (target’s choice) or be knocked prone and take 14 (3d6 + 4) bludgeoning damage plus 14 (3d6 + 4) slashing damage. On a successful save, the creature takes only half the damage, isn’t knocked prone, and is pushed 5 feet out of the bulette’s space into an unoccupied space of the creature’s choice. If no unoccupied space is within range, the creature instead falls prone in the bulette’s space.