Minecraft Dungeons:Key Golem

The Key Golem is a small mob in Minecraft Dungeons which helps the player unlock certain doors upon collection.

Behavior
The Key Golem starts out asleep. When it wakes, it attempts to evade the player any way it can. The player must hit it to collect it, at which point it gets strapped to the player's back. The Key Golem squirms and yells in fear while on the player's back. If the player is damaged while wearing the Key Golem, the Key Golem gets off and flees back to where the player found it. If the player manages to get to a locked door while wearing the Key Golem, it disappears, the lock turns yellow, and then the door opens. There is another Key Golem that is colored blue and is used to open blue doors.

The Key Golem can be picked up by certain mobs. If the mob gets killed, the key has can possibly vanish together, which makes the whole stage unplayable.