Where is he... have you seen him? He has a head like a lightbulb.
Before naughty Blooregard came along I'm thinking he was the house's prime trouble maker. He was central to the episode,
The Big Picture, but I think think he is unique in that we don't actually meet him-was he adopted? He only appears on photos, in flashbacks and in Goo's mind- he walks along cheerfully but gets impatient when nothing happens to him- which reminded me a little of Sonic the Hedgehog.
He is of course, a reference to the beloved children's character,
Where's Waldo! (A book for bored kids a the library who hate reading! Funnily enough that characters name here in the UK is Wally! You must know who I mean- give it a try...
http://www.albinoblacksheep.com/flash/waldo