Captain Underpants Easter Egg - Hidden Characters from Other Books

First, get a copy of Capatain Underpants and the Bionic Booger Boy(I forget the name,it is something like that). Go to the page in George and Harold's comic book where there is a picture of all of the people getting arrested. There will be a line for men,women,boys,girls,babies,dogs,hamsters,and frogs,all walking into diffrent jails. Look carefully at the end of the dog line and the baby line. You will see Super Diaper Baby and Diaper Dog! you will also see Sulu the hamster somewhere in the hamster line. Those are the only ones I have found so far, so keep looking!