Proficiency Bonus +2
Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny snake. The swarm can't regain hit points or gain temporary hit points.
Bite. Melee Weapon Attack: +6 to hit, reach 0 ft., one creature in the swarm's space. Hit: 7 (2d6) piercing damage, or 3 (1d6) piercing damage if the swarm has half of its hit points or fewer. The target must make a DC 10 Constitution saving throw, taking 14 (4d6) poison damage on a failed save, or half as much damage on a successful one.
Proficiency Bonus +2
Keen Smell. The tiger has advantage on Wisdom (Perception) checks that rely on smell.
Pounce. If the tiger moves at least 20 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 14 Strength saving throw or be knocked prone. If the target is prone, the tiger can make one bite attack against it as a bonus action.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (1d10 + 5) piercing damage.
Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.