The line comes from Iron Man, the Marvel superhero played by Robert Downey Jr, whose catchphrase moment I am Iron Man bookends the 2008 Iron Man film and returns in Avengers Endgame in 2019. In Spanish dubs the phrase becomes yo soy Iron Man, and short clipped versions spread on soundboards and in meme edits. Because the full declaration is so well known, even this truncated yo soy fragment is enough for audiences to complete the reference, which keeps it in circulation for introductions, cosplay clips and parody reveals.