Mimic

{u}{u}{u}, {t}: Mimic becomes a copy of target
non-creature artifact, except its name is still
Mimic and it has "{t}: Exile mimic, then return
it to the battlefield under its owner's control.
_______________________________________
"Sometimes a chest is just a chest, but don't
count on it." - X the Mystic's 3rd rule of
dungeon survival.