Complex sentence: Jon Gries returned as Martin Creaser, a hunter and old friend of the Winchesters, in "Citizen Fang", he previously appeared in the fifth season episode "Sam, Interrupted".
Split into simpler sentences: Jon Gries returned as Martin Creaser, a hunter and old friend of the Winchesters, in "Citizen Fang". The character also appeared in the fifth season episode "Sam, Interrupted".