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

Pounce. If the necropanther 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 necropanther can make one bite attack against it as a bonus action.

Running Leap. With a 10-foot running start, the necropanther can long jump up to 25 feet.

Multiattack. The necropanther makes two attacks: one with its bite and one with its claws.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 15 (1d10 + 4) piercing damage and 7 (1d8 + 3) necrotic damage.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damageand 7 (1d8 + 3) necrotic damage..

Mutate. If the necropanther mutates, one of its dead allies that is CR 3 or lower reanimates as an undead with half of its total HP. If the necropanther does not have any dead allies, a zombie rises from the ground to join the combat. It will take its turn in initiative after the necropanther's turn.