Bite

_Melee Weapon Attack:_ +5 to hit, reach 5 ft., one target. _Hit:_ 10 (2d6+3) slashing damage plus 9 (2d8) acid damage. If the target is a Large or smaller creature, it is grappled (escape DC 13). Until this grapple ends, the ankheg can't Bite another target.

Acid Spray (Recharge 6)

The ankheg spits acid in a line that is 30 feet long and 5 feet wide, provided it has no creature grappled. Each creature in that line must make a DC 13 DEX save, taking 18 (4d8) acid damage on a failed save, or half as much damage on a successful one.