Each day in June you'll get an entry showing you the first appearance of seemingly minor characters, phrases, objects or events that later became notable parts of comic book lore. Not major stuff like "the first appearance of Superman," but rather, "the first time someone said, 'Avengers Assemble!'" or "the first appearance of Batman's giant penny" or "the first appearance of Alfred Pennyworth" or "the first time Spider-Man's face was shown half-Spidey/half-Peter." Stuff like that. Here is an archive of what I've featured so far.
First time Aquaman was called Arthur Curry
Aquaman had amazingly been around for 18 years before he finally gained a name other than just "Aquaman," in 1959's Adventure Comics #260, which also saw the debut of his new origin...
First time Cyclops was referred to as "Slim"
Reader LikeAPhoenix wanted to know when Cyclops was first called "Slim."
It was actually in the very first issue of X-Men in 1963!
Although, judging by his abilities of perception, perhaps "dim" would have been a better nickname ("how could the chair be moving after you said you would move it?!? You'd have to have some sort of eXtra power, and that just isn't possible!")
First appearance of Vicki Vale
Batman's Lois Lane substitute made her bow in 1948's Batman #49....
It is kind of amazing how blatant of a Lois Lane riff she was ("Hey, people sure seem to love how Lois is always trying to prove Clark Kent is Superman, let's do that, too!"). _________________________________________________________________________________
Feel free to send in ideas for future debuts I should feature here to email@example.com!