RC Shroober

The RC Shroobers  is a group of 3 light blue Shroob with purple spots that has a pair of radio antennae attached to its head. Using its antennae, an RC Shroober can control electronic devices. The RC Shroobers are found in Yoob's Belly. As such, RC Shroobers were presumably in charge of converting normal Yoshis into additional Yoobs.

There are only 3 RC Shroobers found in the entire game. They appear as a boss in Yoob's Belly. In battle, an RC Shroober summons radio-controlled weapons with its antenna. Its attacks can be predicted based on the antenna it uses and which direction the radio waves point. Two antennae indicate that the RC Shroober will summon a radio-controlled UFO. This flying saucer would hover over a Mario brother and beam him up, causing damage. To counter this attack, Baby Mario or Baby Luigi has to use his Hammer to knock the UFO down as their older counterparts were being beamed up, sending the flying saucer crashing into the RC Shroober. If the radio waves point at Mario, he will have to defend against the UFO; if they aim at Luigi, he is the target.

RC Shroobers can also summon a radio-controlled mobile bomb if they use one antenna. When summoned, this bomb would circle around the brothers, attempting to hit Mario and Luigi and explode. The two brothers could dodge this attack by jumping. If one of the brothers jumped on the bomb, it would malfunction and hit the RC Shroober. Eventually, the mobile bomb would explode on its own without hurting anyone. Additionally, if an RC Shroober jumps before summoning a mobile bomb, the little explosive stalls before starting on its circular path. The direction the RC Shroober's antennae point before the attack indicates which Mario brother the robotic explosive will attempt to attack first, just like with the UFO. An third attack is by transforming the waves in lasers where must be jumped over. The final attack is by throwing the mobile bomb and hammering counters it. However, the bros. eventually defeat the Shroobs and gain access to Sunnycide.