Family Guy crossovers onto American Dad! - At the beginning of 'Return of the Bling', Klaus is ready for school wearing a Brian Griffin cap and Family Guy T-shirt.
American Dad! appearances on Family Guy - Roger makes a surprise appearance in 'Meet the Quagmires' where the timeline has been altered where Roger now.
The event depicts a hurricane which hits the towns of Stoolbend (The Cleveland Show setting), Quahog (Family Guy setting) and Langley Falls (American Dad!