The Beatles were ubiquitous in the 1960s, and it's not surprising they would enter the world of comix. Members of the Fantastic Four met the Fab Four, briefly, Gold Key published a Yellow Submarine comic, and Batman solved a "Paul is Dead"-style mystery involving Beatles knock-offs in #222 of his comic.
Unlicensed references to the Beatles abound. Betty and Veronica listen to the moptops on the cover of the 1965 issue of Laugh; Superman's Pal Jimmy Olsen plans to take Lucy Lane to see them in concert in this issue. They're playing "at Metropolis Stadium Tonight;" did someone update that roadside billboard daily?

This collectibles site chronicles the Beatles' many appearances in magazines, comic books, and elsewhere; its makers collected these (and other) images.