(image borrowed from Wikipedia)
Donald Duck is apparently the only character from Mickey and his friends who has a middle name. It's Fauntleroy.
(image borrowed from Disney Clip Art Galore)
Minnie's cat, Figaro, first appeared as her pet in First Aiders in 1944, four years after he appeared in Pinoccchio. He would continue to appear in cartoons with Minnie and Pluto a few more times and ending with Pluto's Sweater which aired in 1949.
(image borrowed from Disney Wiki)
Roger Rabbit appeared in three other short cartoons called Roller Coaster Rabbit, Tummy Trouble, and Trail Mix-up. He naturally starred in Who Framed Roger Rabbit as well. As to which came first, the book didn't say.
