The former "Happy Days" star will play Chris' (Will Arnett) tough, doting grandmother. While Chris is the apple of Gammy’s eye, she can hardly stand Reagan (Christina Applegate). We sense that there's some family drama on the way.
Ross won't be the only "Happy Days" vet to guest star on the show. Henry “The Fonz” Winkler will play as Ava’s (Maya Rudolph) father in an upcoming episode.
In other casting news...
"ER" vet Anthony Edwards will return to TV in the ABC pilot "Zero Night." It will center on a magazine editor who becomes involved in one the most compelling conspiracies in human history when his wife is kidnapped. [TVLine]
Ken Marino will co-star in "American Judy," ABC's Judy Greer comedy pilot about a cosmopolitan woman who gets married and moves to the suburbs. The "Party Down" star will play Greer's husband, Dean. [THR]
Peta Sergeant has landed the role of Gaia Woods in the CW "Hunger Games"-esque pilot "The Selection." Sergeant's character is described as a rebel leader who is working to overthrow the monarchy. [THR]
"The Finder’s" Mercedes Masohn and "One Tree Hill’s" Robert Buckley have joined the ABC soap pilot, "666 Park Ave."The show will revolve around a young couple that accepts an offer to manage one of the most historic apartment buildings in New York City. [THR]
"Descendents" co-star Amara Miller has landed a role in Fox’s White House drama pilot. Miller will play the daughter of the president (Bill Pullman) in "1600 Penn." [EW]