yes i have seen him many times,but the most noticable one is in mortos der soulstealer when the tube closens up on the screen,right before you see dib.i hope this was any help :)
Yeah, you can find him in the episodes Bad, Bad rubber piggy in the swirling vortex, and in Backseat Drivers from beyond the stars but he is really small next to tallest purples eye when he is saying, "Look! A vort ship!"
