Werecrocodile

Shapechanger. The were-crocodile can use its action to polymorph into a crocodile-humanoid hybrid or into a crocodile, or back into its true form, which is humanoid. Its statistics are the same in each form except for its size and speed. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Hold Breath. The were-crocodile can hold its breath for 15 minutes.

Keen Smell. The were-crocodile has advantage on Wisdom (Perception) checks that rely on smell.

Dreadful Gaze (Humanoid Form Only). The were-crocodile targets one creature it can see within 30 feet of it. The target must make a DC 14 Wisdom saving throw or be frightened for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to the Dreadful Gaze for the next 24 hours.

Regeneration. The were-crocodile regains 10 hit points at the start of its turn if it has at least 1 hit point and isn't in sunlight or running water. If the were-crocodile takes damage from a silvered weapon or a spell, this trait doesn't function at the start of its next turn. The were-crocodile dies only if it starts its turn with 0 hit points and doesn't regenerate.