Hold Breath: The abdhugra can hold its breath for 15 minutes.

Bite: 
Melee Weapon Attack: +4, Reach 10 ft, One target
Hit: 7 (1d10+2) Piercing damage plus 4 (1d8 Acid damage.

Acidic Spit: 
Ranged Weapon Attack: +4, Range 20/40 ft, One target
Hit: 7 (2d6) Acid damage.

Lancing Charge: 
Melee Weapon Attack: +4, Reach 30 ft. Line, Within Line.
Hit: 15 (2d10+4) Piercing damage.
The abdhugra must move at least 10 ft. in a direction towards the creature to perform this action. Those within the line of charge must make a Dexterity Saving throw (DC 15). If failed the target takes 2d10+4 piercing damage and you are considered grappled and restrained as you are impaled by the spear like mandibles of the abdhugra. Anyone behind the target impaled is instead knocked prone. If successful you are not impaled or knocked prone, and take half damage. If you are impaled by the abdhugra the abdhugra cannot make any bite attacks, but can use its acid spit to spill its acidic ooze into the innards of the currently restrained target. The target can escape the grapple by performing a Strength Check (DC 14) to un-impale themselves and set themselves free.

Enter the description for how legendary actions work for your monster here.

Legendary Action Name (Costs # Actions). Enter the description for your legendary action.