Door Mimic

Door Mimics are simple enemies that look just like regular doors. In Ocarina of Time, they do nothing unless Link tries to "open" them, which will make them fall on top of him. Aggravating as that is, they can be quickly avoided once you see them wiggle after attempting to go through them, and as one of the Gorons earlier mentioned, they die rather simply with a Bomb blast. You can easily tell which doors are real because real ones indent into the wall, while fake ones stick out a little ways. Just keep an eye out for this before you open any and you should easily defeat any trickery that would befall you otherwise.

They also appear in The Minish Cap with the same tactics.