Rover

, also known as, are recurring NaN Sub-Bosss in.

Characteristics
Series: is a mysterious round creature with dog-like behavior. It attacks by picking up a heavy Series: and throwing it at Series:, who must pick it up with his Series: and throw it back at Series: before the Series: is able to retrieve it.

LADX: is found in a hidden room in LADX:, in one of the "eyes" on the LADX: map. The only way to access this room is to open the wall with NaN Bombs. After defeating LADX:, a warp to the entrance of the LADX: will appear and LADX: can pass through to a room that contains a secret passageway deeper into the LADX:. However, if he cannot find the passageway, the rooms will loop endlessly. LADX: later appears in LADX: along with other NaN Sub-Bosss, where it will continue to reappear even after being destroyed.

OoA: is found as the OoA: of the OoA: on OoA:. The only major difference from its incarnation is that the OoA: will disappear after a short while after being thrown and reappear closer to OoA:.