PK & SD

Panda-KISS

http://en.wikipedia.org/wiki/Kiss_(band)#History 

http://funnyhot.net/pics/funny-animals/funny-animals11.jpg, http://ultimateclassicrock.com/kiss-pandas

This obviously isn't Scooby-Doo any more than that's not Velma, but there are still some similarities.
www.metro.co.uk/weird/911824-great-dane-zeus-named-the-worlds-tallest-living-dog

Big Bob & little bull.
www.metro.co.uk/weird/911940-stowaway-cat-survives-10-hour-trip-in-owners-suitcase-for-visit-to-disneyland

Or big dog & little bull.
www.metro.co.uk/weird/911774-northern-irish-bull-archie-is-shortest-in-the-world

http://www.funnyanimalsite.com