Apparently S2 of Supergirl will cast a former werewolf (
Teen Wolf’s Tyler Hoechlin) as Clark Kent (but apparently only for a couple of episodes), and a former Wonder Woman (Lynda Carter) as the US President. Also some other familiar DC characters have been cast, e.g. Snapper Carr and Maggie Swayer. Looks like it'll be fun!
http://www.denofgeek.com/uk/tv/supergirl/40487/supergirl-season-2-first-poster-more-casting-news
