The whole thing of Ace appearing in the Gorillaz got me thinking, how deep does this crossover rabbit hole go? Turns out it's pretty far, ignoring bumpers and cutaway gags, here's my autistic theory of why I believe the Gorillaz, Family Guy, King of the Hill, Kim Possible, Rocko's Modern Life, Scooby-Doo, etc all share the same universe.

>The Gangreen Gang Leader, Ace of the PowerPuff Girls makes an appearence in the latest Gorillaz music video 'Humility'
>The Aqua Teens had a cameo in the PPG movie, Meatwad made a cameo apearence in an episode of the Brak Show
>Brak and Zorak are on Space Ghost Coast to Coast
>Dexter from Dexter's Lab made several small cameo apearences on the PPG
>Mac and Bloo from Foster's home makes a cameo apearence in the PowerPuff Girls Rule!!! special
>Mandy from Billy and Mandy had a cameo on Foster's Home
>Billy and Mandy had crossover episodes with the Flintstones and Kids Next Door, as well as having cameo apearences by Ed Edd n Eddy, Scooby-Doo, Yogi Bear, Secret Squirrel, and Huckleberry Hound
>CN Invaded took this further by revealing that My Gym Partner's a Monkey and Camp Lazlo also share this universe
>Series finale of Camp Lazlo revealed that Heffer from Rocko's Modern Life was the actual Scoutmaster, and that Lumpus had him locked in the closet for the whole series
>Scooby-Doo had crossovers with Batman, WWE, Josie and the Pussycats, Speed Buggy, the Harlem Globetrotters, etc. As well as Wile E. Coyote, Roadrunner, and Johnny Quest making cameos on WNSB and SBMI