Aquaman’s monstrous group of villains the trench from DC Comics first appeared in issue one of Aquaman’s New 52 title and are probably the least iconic monster villain on this list.
Fin Fang Foom first appeared in Strange Tales issue 89 in 1961. mostly known as an Iron Man villain he’s essentially a Kaiju he’s a giant alien and one of the most recognizable monsters in comic books.
Tales from the Crypt keeper this dude terrified the hell out of me as a kid both in the old-school comic books and especially the HBO TV series
In at lucky number seven we have Man-Bat you knew one of Batman’s monster villains was going to be on this list somewhere and Man-bat it’s well deserved. Man-Bat first appeared in Detective Comics issue 400 in June of 1970.
Biochemist Dr. Michael Morbius was dying from a blood disease and in trying to find a cure for himself he instead turned himself into Morbius the living vampire
He’s just a classic monster villain that’s been written as anything from Campion Super Friends to Super serious and conflicts like Batman the long Halloween
Marvel’s Man-Thing people think he’s a swamping rip-off but the funny thing is Man-Thing came out before Swamp-Thing not by much literally only two months prior with man thing debuting in May of 1971, and swamping debuting in July of 1971.
Killer Croc was essentially born a monster he’s not a dude who did some experiments on himself that turned into a monster he was born with a genetic mutation giving him reptile skin teeth and sharp claws
Etrigan the demon first appearing in the demon issue 1 in September of 1972. He’s just an all-around awesome anti-hero for those of you who don’t know the demon Etrigan’s soul was fused with the body of the human man named Jason blood
Now for our number one spot, we have none other than the Avatar of the Green Swamp Thing first making his appearance in House of Secrets issue 92 in July of 1971