OK K.O.! Let's Be Heroes was a animated series that aired on Cartoon Network and was somewhat know for the sheer amount of characters that would make appearances on the show. Sadly, Cartoon Network announced in August of this year that the show would not be renewed for a fourth season.
Perhaps the most popular character to show up on OK K.O.! Let's Be Heroes is Sega's very own, and beloved Sonic the Hedgehog — who actually appeared on an episode during the last season of the show right before it was cancelled.
As it turns out, the creators had planned for even more characters from popular series to show up on OK K.O.! Let's Be Heroes, and a recent tweet by Producer Toby Fox gives us a look at some of said characters who, sadly, won't have the chance to show up any more.
What's even more interesting is that among the characters that Producer Toby Fox and OK K.O.! Let's Be Heroes creator Ian Jones-Quartey pitched to networks, before the show was greenlit, we see anime characters from series like Sailor Moon, Astro Boy(Mighty Atom), and even Gundam.
Take a look: