Blok is a superhero in the 30th Century. Born the last of his race on Dryad, his stony physiology makes him incredibly strong and durable. He is a member of the Legion of Super-Heroes, although he originally belonged to the League of Super-Assassins. His long-term romantic partner is the White Witch.
Blok was created by Gerry Conway and Joe Staton, first appearing in Superboy and the Legion of Super-Heroes #253.
Superboy and the Legion of Super-Heroes #253 – Night Of The Super-Assassins!
Five youths seek revenge on six Legionnaires. They believe the heroes destroyed their home planet. They easily defeat five of them and go after their final victim…Superboy.