Firbolg

Firbolgs are a race of giant-kin -- that is, giants who aren't big enough to be "proper" giants, but still bigger than ogres -- introduced in the Monster Manual 2 for the very first edition of Dungeons & Dragons, and have managed to sneak into every edition since. They have the distinct honor of being one of the few giant-kin races that have actually been traditionally playable, if always hindered by the rules -- for example, the 3.5 Firbolg had a Level Adjustment of +18, showcasing just how ridiculous that mechanic could get.

In general, they're described as neutral-with-good leanings, being a reclusive and fairly reasonable race of giants. They look very human, essentially appearing as 10ft tall Irish Celts, probably because their name is taken from a race of mythical, magical giants in Irish Celtic folklore. Perhaps because of this, 4th edition tweaked them into a race of fae giants who worship a Maiden/Mother/Crone trinity (Sehanine, Melora and The Raven Queen respectively) and who engage in the Wild Hunt.

Playable versions of the Firbolg appeared in the Book of Monstrous Humanoids (AD&D) and the Monster Manual 2 (3.5); they've officially been proclaimed as one of the monstrous races that will appear in 5e's Volo's Guide to Monsters.Monsters