Beep-0 is a character in Mario + Rabbids Kingdom Battle. He is a small circular robot with blue and lights on his body. However, they can turn red when he is angry. Beep-0 gains white ears when he is presumably merged with a Rabbid, though the merging is never shown, only him gaining the ears.
Beep-0 appears throughout the entire game. As the movement operator in battles, he also appears when walking around the world map.