Arrow co-creator/executive producer Marc Guggenheim spoke about the casting saying, "For eight years, Arrow has stood on the shoulders of Smallville. Simply put, there would be no Arrow, and no Arrowverse, without it. So when we first started talking about Crisis on Infinite Earths, our first, second and third priorities were getting Tom to reprise his iconic role as Clark Kent. To say that we're thrilled would be a Superman-sized understatement."
The crossover will be titled "Crisis on Infinite Earths" and will be a huge gathering of the Arrowverse including Arrow, The Flash, Supergirl, DC's Legends of Tomorrow and Batwoman. The event will take place over a five-episode span in December and January.