Comic book supervillain, published and owned by DC Comics. His first appearance was in The Doom Patrol #89 in August 1964; he was created by Arnold Drake and Bruno Premiani.
Now let's talk about DC Comics during the 1960s and the Silver Age of Comic Books. DC had a reputation of being the comics publisher run by the old fuddy-duds, compared to the younger, hipper kids at Marvel. And yes, DC had Batman as a sworn deputy of The Law, Superman as a strong-jawed conservative, and the Teen Titans as the bunch of teenagers with weird slang because they were written by old men who hadn't talked to any actual teenagers in 20 years.
But DC had one thing that made them cool. Okay, maybe not cool, but we'll say retro-cool for people nowadays reading these old comics. Namely, DC's writers had extremely wild imaginations and a willingness to use characters who were just extremely weird. The Metal Men were loco from top to bottom. Metamorpho comics tended toward the weird. Batman was running around in rainbow costumes, Superman had Red Kryptonite turning him into monsters and freaks, Jimmy Olsen turned into Elastic Lad and the Giant Turtle Man, and the Flash was constantly getting turned into a wooden puppet, or growing immensely fat, or sprouting a giant brain.
In comparison, the Doom Patrol, often dubbed The World's Strangest Heroes, weren't really all that unusual. But some of their villains were pretty far out there. And Animal-Vegetable-Mineral Man was likely the weirdest.
His bio goes like this: Sven Larsen was a former student of Dr. Niles Caulder, the leader of the Doom Patrol. The two had a falling-out after Larsen claimed Caulder had stolen his plans for an anti-decay ray. Larsen then fell into a vat of amino acids, which gave him superpowers. He gained the power to transform any part of his body into any animal, plant, or mineral -- but he also ended up with the most bizarre appearance of almost any character in the Silver Age.
Larsen ended up with the right arm and leg of a tree, and a left arm and leg made of diamonds or another crystal. Half of his torso was human, and the other half was a dinosaur. Atop that was a full head and neck of a dinosaur, with half of Larsen's head merged into the dinosaur's neck. He attacked Caulder and the rest of the Doom Patrol, but was defeated and had his powers taken away. Of course, he later regained his powers and weird appearance and attacked the Patrol again. He was usually a Doom Patrol villain, but he'd show up occasionally if another comic needed a really weird and somewhat comical antagonist.
Animal-Vegetable-Mineral Man has been adapted only a few times. He was in an episode of "Batman: The Brave and the Bold," where he was voiced by Dee Bradley Baker, and he showed up a few times in the wonderful "Doom Patrol" TV series, where he was portrayed as an even more bumbling disaster by Alec Mapa.