Mammoth

5e compatible shield

Huge beast, unaligned

Armor Class 13 (natural armor)
Hit Points 126 (11d12 + 55)
Speed 40 ft.

STR DEX CON INT WIS CHA
24 (+7) 9 (-1) 21 (+5) 3 (-4) 11 (+0) 6 (-2)

Saving Throws 
Skills 
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses passive Perception 10
Languages --
Challenge 6 (2300 XP)

Trampling Charge. If the mammoth moves at least 20 feet straight toward a creature and then hits it with a gore attack on the same turn, that target must succeed on a DC 18 Strength saving throw or be knocked prone. If the target is prone, the mammoth can make one stomp attack against it as a bonus action.

Actions

Gore. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 25 (4d8 + 7) piercing damage.

Stomp. Melee Weapon Attack: +10 to hit, reach 5 ft., one prone creature. Hit: 29 (4d10 + 7) bludgeoning damage. A mammoth is an elephantine creature with thick fur and long tusks. Stockier and fiercer than normal elephants, mammoths inhabit a wide range of climes, from subarctic to subtropical.