Robette is one of Romeo's inventions. Contrary to what Romeo actually wanted, it began to try to take over the world herself in "Catboy and Gekko's Robot Rampage". This was due to a loose screw and was later resolved. During the episode, Romeo's original robot became jealous of Robette, which resulted in the robot running away. This was also later resolved and Romeo became friends with Robot again. She will return in Season 2. 
Robette was generally nice and helpful but turned evil as previously mentioned. Robette was even nice to the PJ Masks, to Romeo's disappointment.
Robette is smaller than Robot and is dark red in color. She has a yellow "eye" which turns red when she malfunctions, with two arms and legs.