McFarlane and Capullo revealed the partnership through their Twitters. Although the two have had a working relationship for some time, McFarlane revealed that this is the first time they've ever "drawn side by side." Neither tweet reveals what the project is, though McFarlane's hashtags indicate it will be published through Image Comics. It's also unclear which of them will write the comic, or if they're working with a third person.
* History... over 60 years of comic book experience between @GregCapullo and I... this is the 1st time we've drawn side by side.— Todd McFarlane (@Todd_McFarlane) March 24, 2019
TODD #first #artists #dccomics #imagecomics #pals pic.twitter.com/oJh7nt6XFd
McFarlane revealed in 2015 that he and Capullo were working on a Batman/Spawn crossover, which never actually materialized. It's unclear if this new project is related to that one, though it's unlikely.
Capullo is arguably most famous for his work with Scott Snyder on Batman. However, the artist has worked in the industry for decades and earned critical acclaim for his work on various titles, including McFarlane's own Spawn. Capullo's comic The Creech was published through Image Comics in 2002. In addition to being part of the team that founded Image Comics, McFarlane is famous for creating Spawn and designing Venom.
McFarlane is also currently working on a new live-action adaptation of Spawn. Written and directed by Todd McFarlane, Spawn is set to star Jamie Foxx and Jeremy Renner. The movie does not currently have an announced release date.