Cage

A cage is found in both Croc: Legend of the Gobbos and Croc 2 with very similar functions. They can only be unlocked using a silver key in Croc 1 and a key in Croc 2, and have been known to hold the following:
 * Gobbo
 * Button

Trivia

 * In Croc: Legend of the Gobbos, King Rufus is seen locked in a Cage, but instead of needing a silver Key to unlock, Croc merely tail-attacks it to free Rufus after defeating Baron Dante. This is the only instance where a key is not required to unlock a cage.