https://motherboard.vice.com/en_us/article/gy73k4/super-smash-bros-ultimate-glitch-creates-a-gazillion-waluigis

If you’re a Super Smash Bros. Ultimate player pining for Waluigi to be put in the fighting game as a playable character, you’re still out of luck. But a newly identified glitch can fulfill your wish in the most twisted way possible—and give you an entire screaming horde of Waluigis.

According to YouTuber TheAfroJow—and spotted by Nintendo Life—if two players are fighting as the character Isabelle, it’s possible to trigger a glitch that spawns a seemingly infinite number of Waluigi assist trophies. The result is extremely cursed (or blessed, depending on how you feel about Waluigi), as Waluigis fill the screen and their insane laughter crescendos into pure chaos.