Guy who played Russ
From Tardis Wiki, the free Doctor Who reference
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 Ross Geller, which would, by extention, make this unnamed actor a parody of Ross's actor, David Schwimmer.