A green lock is a tile in Chip's Challenge that remains as an acting wall until and unless Chip collects a green key. This will cause the tile to be acting dirt, as it will disappear when Chip steps on it. Unlike the other locks, the green lock does not destroy the key used to open it. Large sections of a level filled with green locks often require Chip to find the key and then open a large number of locks - sometimes finding items underneath.