An interaction between Rick and Marvin the Martian in MultiVersus implies that one of the most famous Looney Tunes is a party animal who does space drugs.
One of the best things about MultiVersus is how much love and care it puts into each fighter on the roster, both in how their moves represent them and the series they come from, and the funny interactions they have with other characters on the roster. There are tons of great interactions between specific characters already, but Marvin the Martian has some of the best in recent memory, with one even having some interesting implications.
As highlighted by Twitter user MrWhite4MVS (keep fighting the good fight), Marvin the Martian has a few unique interactions with Rick Sanchez. That's probably no surprise considering the pair are both antihero characters with a focus on space, but Marvin can make one particular comment that I'm shocked made it past Warner Bros. without a fight.
When playing on a team with Rick, Marvin has a chance of saying, "Where do you source your Kalaxian Crystals? Asking for a friend". Rick and Morty fans will likely remember Kalaxian Crystals from the episode "Ricksy Business", where Rick crushes them up and snorts them, giving him the necessary strength to do the Rick dance.
Assuming that Marvin isn't just the nicest friend in the world, the line is clearly supposed to imply that he wants to get his hands on Kalaxian Crystals for... reasons. Viewers are initially led to believe that Kalaxian Crystals have some kind of teleportation purpose, but it seems like all they're good for is a "strong but fleeting high". Hope it's worth it, Marvin.
Unfortunately, because both Rick and Morty use voice clips from the show instead of having newly recorded dialogue, Rick doesn't have any kind of smart or helpful answer to give Marvin, so we're left with half of a legendary encounter. Let's hope the two share some Kalaxian Crystals and get a bit more chatty soon.