Scooby-Doo's doghouse is the one he used when he was a puppy, growing up at the Rogers home.
Physical appearance
It appears small on the outside, but inside it's a huge mansion.
History
A Pup Named Scooby-Doo
Season one
Insert details here. (A Bicycle Built For Boo!)
It was invaded by the Sludge Monster from the Earth's Core.
Season two
Scooby left a goodbye note on the doghouse before running away because he felt neglected.