Alan Brady on Mad About You.
(ETA ninja’d between screen refreshes.)
Harry Morgan (Col Potter-ret.), William Christopher (Father Mulcahy) and Jamie Farr (Klinger) all appeared in “AfterMASH”, a sequel to MASH that ran for a couple of seasons.
Alfre Woodard appeared in an episode of Homicide: Life on the Streets as her St. Elsewhere character, Dr. Roxanne Turner.
While checking to see if any of the characters from Mary Tyler Moore showed up on Lou Grant, (they didn’t), I found that Lou Grant was in an episode of Roseanne. Go figure.
Mr. Anderson on Beavis and Butthead was not only the inspiration for Elrond from Lord of the Rings, he was also clearly the inspiration for Hank Hill from King of the Hill.
Woody also appeared on Frasier.
Ray Barone appeared on King of Queens, as did his mother (but I’m not sure if it was while ‘Raymond’ was in production).
mmm
Does sketch comedy count? Surely there have been SNL guests who have played their characters from other shows? The only specific example that comes to mind is when Lenny and Squiggy (from Laverne and Shirley) made an appearance in a sketch during the season when Michael McKean was a cast member.
Huh? What? Huh? Is this a whoosh? How is Mr. Anderson like Elrond?
Elrond was of course a character before Mike Judge was born.
This website is a list of all the crossover universes from American television. The largest of the universes is Group 2, which has over a hundred shows in it. The list of groups is at the bottom of the webpage:
There was an episode of The Simpsons where Homer goes looking for a new bar, and wanders into Cheers. All the regulars except Frasier had one line each.
An episode of Amazing Stories had several TV characters come to life. Characters appearing from cancelled shows included June Cleaver, Aunt Esther Anderson and the Hulk. (Gary Coleman and Dirk Benedict’s shows were still current at the time)
…yeah, Munch pretty much is the exemplar of this topic. A wiki summary:
ABC’s “Civil Wars” lawyer Eli Levinson and his secretary Denise jumped from their show over to NBC’s LA Law after their show got cancelled.
Better Call Saul is a spinoff prequel to Breaking Bad. Saul Goodman/Jimmy McGill is the titular character and Mike is also a focus character who’s been in the whole series, so don’t count by your rule although they were in both. There are a ton of characters other than those two who have appeared in both series - Gus Fring, Lydia, Gale, Tyrus, Hector Salamanca, Tuco Salamanca, the Salamanca cousins, Don Eladio, Juan Bolsa, Crazy 8, the gun dealer, Huell, Vanamos Pest guy, Francesca, and Vacuum repair guy just to name the ones I can think of. This page seems to have a more comprehensive list: http://www.vulture.com/2018/09/breaking-bad-better-call-saul-crossover-characters.html
Munch and Fin showed up on an episode of 30 Rock. Batman and Robin were on some version of Scooby Doo, as were the Addams Family. Superman was on I Love Lucy. Sheriff Andy Taylor cameoed in the first episode of Gomer Pyle, USMC.
Your mention of Dirk Benedict reminded me: there was an episode of The A-Team in which Face (Dirk Benedict, who had played Starbuck on Battlestar Galactica) ran across a Cylon while at a theme park.
Carol Kester (Marcia Wallace) and Bob Hartley (Bob Newhart) appeared on an episode of Murphy Brown sixteen years after The Bob Newhart Show had ended.
Three (or four?) Klingons from TOS showed up for an episode of DS:9. One was Kang, another was the one from Trouble with Tribbles, and I think the third was the one where Kirk supplied guns to the American rebels after the Klingons started giving the Chinese guns?
No. It was Kang (Michael Ansara) from “Day of the Dove,” Kor (John Colicos) from “Errand of Mercy,” and Koloth (William Campbell) from “The Trouble with Tribbles.”
The spy “Arne Darvin” (Charlie Brill) from “The Trouble with Tribbles” was in an episode as well. Was it the same one?
This is suspect, all things considered*, but Reginald Veljohnson appeared in an episode of Chuck as his character from Die Hard, Sgt Al Powell.
*in other episodes of Chuck, Die Hard is clearly referenced as a fictional movie
Jack Riley played Mr. Carlin, the misanthropic real estate tycoon, on The Bob Newhart Show. Riley later did a cameo on Newhart, presumably as Carlin. He was described to Dick Loudon (Bob Newhart’s character) as having been “messed up” by “some quack in Chicago”.