Co-writer Christopher Markus happens to be a big fan of M.O.D.O.K. and tells the L.A. Times Hero Complex, "I love MODOK and I think you could make a terrifying movie with MODOK but nobody seems to be on my side at the momentum.”
Markhus continues noting that First Avenger pulled off the Red Skull really well, so why not M.O.D.O.K.?
”In this movie, the great thing is [the visual effects and makeup team] really pulled off the Red Skull. It doesn’t look like a mask. it looks like it’s fully integrated into his flesh. And I want to see what they can do with MODOK.”
M.O.D.O.K. stands for Mental Organism Designed Only for Killing, and is basically this giant floating head with small arms and legs that can mind control.
Personally, I can't stand the character of MODOK, and hope as heck they don't use it for the Cap sequel.
Word appears to be they want to keep Cap in the WWII setting, which is hopefully the case.
Regarding M.O.D.O.K. - I say thee nay!