Well, it's been a while, but we finally have a Fearless Fly adventure available from the Milton The Monster Show. Fearless & Milton turn 50 this year, and around October, we're going to feature Milton as much as possible. For now, here's Fearless in "Invincible vs. Invisible". Bob McFadden does most of the voices, if not all of them, as he's the only one credited. The open to Milton precedes our feature.
As we've noted before, Fearless wasn't the only super insect to debut in 1965. Hanna-Barbera's Atom Ant also turns 50, but his shorts are not as readily available thanks to WB keeping them under tight wraps.