Guy who played Russ

Whilst filming the final episode of the show Chums in 2014, the guy who played Russ suddenly turned into a frog, as a side-effect of Rose-the-cat trying to create a cat flap in the Doctor's TARDIS. (COMIC: A Rose by Any Other Name)

Behind the scenes
Russ is a clear parody of the Friends character, which would, by extention, make this unnamed actor a parody of Ross's actor,.