The first, a griffon character in My Little Pony: Friendship Is Magic, appeared in episode 5 of season 1. Did the griffons appear in any of the three earlier generations, or is this their first appearance in the franchise?
I didn't see all the earlier series, movies and comics before G4.
No. G1 and G2 only had ponies, pegasi and unicorns (plus some odd winged unicorns that were animation mistakes). The various cartoons also introduced human friends as well as a solitary dragon, mud-monsters, spiderlings, bushwoolies (don't ask), porcines, zebras, goats, flowerlings, monkeys, bulldogs and leprechauns as the antagonists.
G3 introduced a raft of new animal friends including ladybugs, birds, and mer-ponies but no griffons.
G4 then introduced all sorts of other animals such as cows, adult horses, griffons, cats, deer, Klugetown monsters, mermares, hippogriffs and Transformers (both Autobots and Decepticons).
