The Kroom leader, from the season two He-Man episode "Trouble in Trolla", was always one of my favorite characters. He pretty much steals the show in the one scene he appears in, in which he orders one of his henchmen to close the gates to their fortress. The character was designed by Charles Zembillas, one of the foremost character designers on the show. What I love most about the design of the Kroom leader is that his eyes are so wildly expressive! Also, there is just something naturally funny about a pig-sized warrior sporting ostentatious armor!
(click on the image to see it at full-size)