I believe Harlan Ellison wrote a couple of the first episodes, but quit when he realized how the plots were going to go. After the 3rd or 4th big head with silver hair appearing in space, I agreed with Ellison.


ah...right.. "Ellison has repeatedly criticized how Star Trek creator and producer Gene Roddenberry (and others) rewrote his original script for the 1967 episode "The City on the Edge of Forever"."