It seems the first villain Luke Cage (Mike Colter) will be squaring off against in his solo TV show will be one of the first he encountered in the pages of Power Man way back in 1974. Heroic Hollywood reports that Cornell Cottonmouth (not to be confused with the Serpent Society member) is going to be causing problems for Cage when Marvel's third Netflix series finally gets underway.
It sounds like he'll be introduced as a second tier baddie, working for the show's main antagonist, and may also have ties to Daredevil's Wilson Fisk. In the comics Cottonmouth has super strength and razor sharp golden teeth, but it remains to be seen if that'll carry over into live-action of course.
The only other detail we have on Luke Cage so far is that Cheo Hodari Coker (Southland, Ray Donovan) is on board as showrunner, but we should hear some official casting info pretty soon.