Yellow teleport
The yellow teleport is a tile introduced in Chip's Challenge 2. They will attempt send movable objects to another yellow teleport in reverse reading order if the exit direction is not blocked. If the exit directions for all yellow teleports are blocked, the movable object will put the yellow teleport in their inventory. In the case of Chip, Melinda, ghosts, and rovers, this means that yellow teleports later can be dropped elsewhere.
Yellow teleports are technically not items but are instead treated as terrain, thus they can only be dropped on floor and no signs will not affect them.