D&D 5th Edition Data Explorer

Charge
If the boar moves at least 20 ft. straight toward a target and then hits it with a tusk attack on the same turn, the target takes an extra 7 (2d6) slashing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.
Relentless
If the boar takes 10 damage or less that would reduce it to 0 hit points, it is reduced to 1 hit point instead.
usage:
rest types:
short
long
type:
recharge after rest