Yes, Cockrum created or co-created (and designed) all three of those characters during his time with Len Wein. I also believe he had a hand in Mystique, too. His revamp of the LOSH in the 70's before his X-Men run was also key (Nightcrawler was originally designed to join the Legion). He also created Thunderbird I, whom at the con that I spoke to in 2002 or so he admitted "was basically the same as Wolverine so they felt the need to kill off one", and they went to keep the Canadian Wolverine. Granted, without Thunderbird, there'd probably be no Warpath, who Brubaker is currently making "hot" in his Uncanny run. Claremont & Bryne got a lot the credit for the "new" X-Men but Cockrum's role shouldn't be overlooked. He was also Marvel's key cover artist during the late 70's. After THE FUTURIANS failed to take off after 1983 he sort of slipped outside the limelight, which was a shame.