Warning: contains major spoilers for Giant-Size Little Marvels #3!
Dubbing Rocket Raccoon "Trash Panda" was one of Star-Lord's most humorous moments in Guardians of the Galaxy Vol. 2. The nickname has stuck among fans, though it seems to be having a harder time sticking in space. Giant-Size Little Marvels #3 stars Rocket Raccoon and Groot in a search for a mysterious object called the "Death Stone", leading them to ask some questions to the Mad Titan himself.
After the Guardians are saved by Ego, Rocket and Star-Lord end up bickering with the latter calling the former a "raccoon". This results in Rocket becoming very angry, to which Star-Lord apologizes before calling him a "trash panda," before saying it's actually a worse thing to do. Trash panda is now a term that has stuck with fans who use it regularly and it turns out, Rocket may actually be a fan of it himself - at least over other things.
Giant-Size Little Marvels #3 is a new Infinity Comic from Marvel that has the creative team of Skottie Young, Dax Gordine, Jean-François Beaulieu, and Blambot's Nate Piekos. Within this issue, the Collector asks Rocket and Groot to bring him the Death Stone. The name leads them to believe they are looking for an Infinity Stone. Knowing about Thanos' obsession with the stones, they seek out the Mad Titan himself - but he just can't get Rocket's nickname right.
While asking Thanos about the stone, he continually refers to Rocket as a "Trash Possum." Groot inquires about it and his friend says Thanos means "trash panda." When the mistake is repeated, Rocket is visibly annoyed when he responds with "panda." This exchange initially just seems humorous, but it reveals a truth about Rocket Raccoon. Despite having "Raccoon" in his official name within Marvel comics and films, he prefers trash panda. If the entire nickname were bothersome, he would likely provide "Rocket" as his preferred name. Instead, he becomes more irritated at the animal selection being incorrect. He finds trash pandas more appealing than trash possums. Although possums and raccoons are both nocturnal and he IS a raccoon, panda is the only acceptable alternative from his perspective.
Considering the outrage that Rocket unleashed on Star-Lord when called a raccoon, it is surprising that he would accept trash panda in any way. This is especially true since Star-Lord admitted to it being the worse of the two names he called him. All things considered however, it could be worse. Possums root through trash like pandas do, but they're better known for playing dead. This isn't a skill Rocket prides himself on. He is a master at constructing weapons and blowing things up. He also looks nothing like a possum. While he doesn't resemble actual pandas, he does share the same color variation that gave other raccoons that comparison. Visually, it is far more fitting and apparently, more acceptable to him as a nickname. The Guardians of the Galaxy's Rocket Raccoon will rage against the second half of his own company-given name, but trash panda is a name that is here to stay - by his own admission.