Ankheg

Large monstrosity, unaligned

Armor Class 14 (natural armor), 11 while prone

Hit Points 39 (6d10+6)

Speed 30ft., burrow 10ft.

Senses darkvision 60ft., tremorsense 60ft., passive Perception 11

Languages -

Challenge 2 (450 XP)

Actions

Bite

Melee Weapon Attack: +5 to hit, reach 5ft., 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 30ft long and 5ft 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.