1st team appearance of the Skrulls, the shape-shifting alien race

2nd team appearance of the Fantastic Four

1st appearance and origin of Thor

Introduction of Thor's hammer, Mjolnir

1st team appearance of the Kronans, a race of rock-like aliens

1st appearance of Donald Blake, the human host of Thor

1st team appearance of the Xartans, an alien race of shapeshifters

1st appearance of the Watcher

1st appearance of the Red Ghost and his Super Apes

Origin of Odin

1st appearance of Buri, grandfather of Odin

1st appearance of Bor, Father of Odin

1st cameo appearance of Surtur

1st cameo appearance of Ymir

1st appearance of Vili and Ve, Odin's brothers

1st appearance of Kree Intergalactic Sentry 459

First mention of the Kree alien race

1st team appearance of the Dominators, an alien race

First solo ongoing Silver Surfer series

Origin of the Silver Surfer

Origin of the Watchers

1st appearance of Shalla-Bal

Silver Surfer first says, "where soars the Silver Surfer...there must he soar alone!"

1st appearance of Badoon

1st team appearance and origin of the Guardians of the Galaxy

1st appearance of Major Vance Astro

1st appearance of Charlie-27

1st appearance of Martinex

1st appearance of Yondu

1st appearance of Arkon, a warrior from an alien planet and an ally to the Avengers

1st appearance of Tamara Rahn, the last survivor of a water-breathing alien race known as the Banari

Origin of the Kree/Skrull war

Origin of Mantis

Origin of Vision

1st full appearance of the Cotati, a plantlike humanoid race

1st appearance of Threkker, an Epsiloni alien who absorbs life from other living organisms

1st cameo appearance of Lilandra, fully obscured by a spacesuit

1st appearance of the second Erik the Red, a scout and warrior for the Shi'ar

First use of the name Polaris by Lorna Dane

Revealed that Colossus's first name is Peter

1st appearance of Ajak, a member of the sub-group known as the Polar Eternals

1st appearance of Arishem the Judge, a Celestial

The Celestials sink the Kingdom of Lemuria and as a result, Atlantis is also sunk

[July 2022 - Marvel recently trademarked the title Celestials: End of Time]

1st appearance and origin of Nova, Richard Rider

1st appearance of Rhomann Dey, Corpsman of the Nova Corps

1st appearance of Robbie Rider, brother of Nova

[January 2021 - the MCU maintains their intention to use Nova (Alexander & Rider) in a film / March 2022 - Deadline reports a source confirms a Nova project is in development]

1st team appearance of A'Askvarii, an alien race

1st appearance and origin of ROM

1st appearance of the Prime Director

1st team appearance of the Dire Wraiths and the Spaceknights

[December 2019 - Hasbro recently closed a multi-billion dollar acquisition of an entertainment company with the purpose of expanding its brands into movies & television. SPECULATION: ROM is likely a candidate]

1st appearance of Grant Wilson aka Ravager, Deathstroke's son, not in costume

2nd team appearance and origin of the New Teen Titans: Beast Boy, Cyborg, Kid Flash, Raven, Robin, Starfire and Wonder Girl

2nd appearance of Starfire

2nd appearance of Cyborg

2nd appearance of Raven

1st team appearance of the Brood

1st appearance of the Brood Queen

Origin of Corsair

1st appearance of the Acanti, an ancient race of aliens that are described as space whales

1st appearance of alien race Ba-Bani

1st appearance of Beta Ray Bill, a Korbinite alien worthy of picking up Mjolnir

1st appearance of Lorelai, the sister of Enchantress

[July 2022 - is the actress who plays Sif teasing a future announcement of a “buddy cop” series with Beta Ray Bill? This Instagram post hints at that possibility - see additional pics / The Korbinite race exists in the MCU as proven on the Grandmaster's Tower in Thor Ragnarok]

1st appearance of Spider-Man's black costume

Cover art inspired by Amazing Fantasy #15

The symbiote costume was designed by a Marvel fan from Illinois named Randy Schueller. Editor-In-Chief Jim Shooter purchased the design idea from Randy for $220

Origin of the Savage Land

1st team appearance of the Nuwali, an ancient race of aliens who built the Savage Land

Cover art inspired by Nick Fury, Agent of S.H.I.E.L.D. #6 (1968)

1st appearance of Sleepwalker

1st cameo appearance of 8-Ball, on a TV screen

1st full team appearance of The Phalanx in their true form

Cameo in #305, hinted at when Rogue touches what seems to be a normal human and #311 briefly in their true form

1st appearance of the Chitauri

1st appearance of Corvus Glaive of the Black Order aka Cull Obsidian, an elite mercenary squadron under the command of Thanos

1st team appearance of the Outriders, an army engineered to serve Thanos

Captain Marvel's cat, Chewie revealed to be an alien species known as a Flerken

1st appearance of Pik Rollo, a Ruu'ltoian assassin resembling a Giant Panda

1st appearance of a Progenitor, an alien race that experimented on the Kree, creating a powerful warrior race from savages