Calcifer

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

Cone. Calcifer has disadvantage on Wisdom (Perception) checks that rely on peripheral sight.  While wearing the cone, nibbles is inactive.

Familiar. Calcifer can serve another creature as a familiar, forming a telepathic bond with his willing master, provided that the master is at least a 3rd-level spellcaster. While the two are bonded, the master can sense what Calcifer senses as long as they are within 1 mile of each other. If his master causes him physical harm, Calcifer will end its service as a familiar, breaking the telepathic bond.

Feet. Calcifer has a natural attraction towards feet.

Nibbles. If the cone is removed, role a DC 20.  On a fail (under 10), Calcifer takes 1 slashing damage.  

Claws. Melee Weapon Attack: +0 to hit, reach 5 ft., one target. Hit: 1 slashing damage.

Headbutt. Melee Weapon Attack: +1 to hit, reach 5 ft., up to 3 targets.  Hit: 3 bludgeoning damage.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 3 piercing damage.