Crocodile

The Crocodile is a character from the Neverland world, and one of Captain Hook's enemies. He acquired a taste for the pirate captain when Peter Pan chopped off the captain's hand and fed it to him. He now follows Hook around everywhere, hoping to get a second taste of the captain. The crocodile isn't quite a villain, since he primarily hunts Captain Hook, but he does attack Sora and Ventus.

The crocodile swallowed a ticking alarm clock, that now, unfortunately for the crocodile, warns Captain Hook if he is approaching. This has become something of a trademark for the crocodile, foreshadowing its arrival in a way that terrifies the captain, much to his humiliation.

Kingdom Hearts
''A seagoing reptile big enough to swallow a man whole -- and he's always hungry! He got a taste of Hook once and never forgot it. Hook can tell when he's near by the sound of the clock ticking away in his stomach.''

He had a taste for Captain Hook in "Peter Pan" (1953).

Kingdom Hearts Birth by Sleep
Peter Pan (1953)

Captain Hook's most feared enemy.

Just a few ticks of the clock he swallowed are good enough to send Hook running for dear life.

Kingdom Hearts Birth by Sleep
The Crocodile plays a small role in Terra's story when it shows up in the Skull Cave and scares Captain Hook away. It also appears during Ventus's story in the coast shortly before his fight with the captain. During Ven's fight, the Crocodile swims around in the water, attacking Ven if he gets too close and attacking the Captain if Ven successfully knocks him into the water, hurting and scaring Captain Hook back onto the rock. After the fight, the Crocodile chases Captain Hook back to his ship. It later appears once again in the gully in Aqua's story to frighten Hook away for a third time.

Kingdom Hearts
The Crocodile plays a small role at the end of the storyline in the Neverland world though he is mentioned before then. After Sora and Peter Pan defeat Captain Hook, the Captain falls into the water only to be chased away by the Crocodile. This is almost identical to his fate in the movie (although since he appears in Kingdom Hearts 358/2 Days, it is presumed that he escaped).

Le Crocodile Krokodil