Barney Goodles horse was Sparkplug. Years ago I bought a banjo-uke at a flea market only because it had a pen and ink drawing of Barney and Sparkplub on the head. (unsigned, so I don't know if it was by the strip's creator) Snuffy Smith was originally a minor character in the Google strip, which was created by (I think) Billy DeWolf. I don't know if he was the writer when Smith was introduced.

Batman - Bruce Wayne, the butler was Alfred.

Henry never spoke a word.

Maggie and Jiggs' strip was "Bringing up Father", I think. He hung out at Dinty Moore's, which is the name of a canned beef stew.

Prince Valiant is the knight on KA's round table

Smokey Stover is the strip with the firemen. (Notary Sojac)

Lothar was Mandrake's sidekick. Don't know the creator, but he's the same guy who did the Phantom. (which was a great under-rated movie back in the 90's)