Rob has a light blue body, and a yellow head and feet. He has dark blue hair in two spikes, and wears a pink headphone. He has red pupils. Rob shares a similar appearance to Raymond.
Gaston is also light blue colored. He has gray tube-like arms. Gaston also has a big yellow mouth, and it looks like it is stuck in that position. He has a gray screw on one side of his head and black pupils. Gaston shares a similar appearance to Jethro.
They ride on a cannon and attempt to blast K.O. and Dendy in their buggy.
Rob and Gaston have not shown up in the show yet, so there is a chance that they aren't actually canon, at least in the show's universe.