Groot
A tree-based superhero.
Where is he from?
Groot is an OOOOOOOOLD Marvel character, dating all the way back to Tales to Astonish in 1960, predating even the Fantastic Four, when Marvel was mostly doing monster stories. He was a tree monster from space that came to Earth to kidnap and study humans. He spent decades sitting in the backlog of characters before he was pulled out for the Annihialation corssover in 2007, a deep-dive into Marvel's space-based characters... and it's follow up series, a weird little book called Guardians of the Galaxy...
That weird little book, in the hands of screenwriter Nicole Perlman & director James Gunn, became one of the best MCU movies and maybe best sci-fi romps of all time, Guardians of the Galaxy. While a lot of Groots characterization as a loveable but almost magically powerful brute was developed in the comics, it was the movie that made him a beloved icon. Vin Diesel does his voice, even when he regrows into Baby Groot in the sequels.
Comic Appearances
GND 266 - Sarah & Christine head to campus, mentioning Chihiro, Edmund, River Song, Peter Petrelli, Dr. Ian Duncan, & Raoul on the way. They pass the Uni Club Fair, where Rey, Kaylee, & Mako are hanging by the Mechanics Club booth with Rocket & Groot. Meanwhile Capable, The Dag, baby Wick, & Toast the Knowing are encouraging Nux to join.