I'm sure there's plenty of it on the internet. Not sure if it truly counts as a transformation however. As an example here's an episode of "Brickleberry" that does exactly that:
https://www.watchcartoononline.io/br...ode-6-gay-bomb
(Warning, Brickleberry is the twisted love child of Family Guy and South Park. With all the vulgarity and none of stuff that made the parent shows good in the first place. Watch with absolute caution and prepare the Brain Bleach for afterwards.)