Bite

Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4+2) piercing damage or 7 (2d4+2) piercing damage against a creature the weasel is grappling.

Grab

Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: The target is grappled (escape DC 12).