Keen Smell. The zecal has advantage on Wisdom (Perception) checks that rely on smell.

first blood. During its first turn, the zecal has advantage on attack rolls against any creature that hasn't taken a turn. Any hit the zecal scores against a surprised creature is a critical hit.

Pounce. If the zecal 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 18 Strength saving throw or be knocked prone. If the target is prone, the panther can make one bite attack against it as a bonus action.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage.

Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) slashing damage.