Mark Desmond worked in the secret underground labs at Project Cadmus creating and cloning genomorphs. His crowning accomplishment was that of the Super Boy, a clone of Superman. When Dubbilex orchestrated a fire that attracted the attention of the proteges of the Justice League, Desmond took the Blockbuster serum to defeat Aqualad, Kid Flash, Robin and the rogue Superboy. Robin and his team took out the building's support beams, bringing it down on Blockbuster's head. The Justice League appeared and Superman assisted Green Lantern in taking Blockbuster to the appropriate authorities.
- Superhuman Strength: As Blockbuster, Desmond was strong enough to take on super-powered enemies.
- Superhuman Durability: As Blockbuster, Desmond was durable enough to survive a building collapsing directly on him.
- Science: As a human, Desmond was a skilled scientist.
- Diminished Intellect: As Blockbuster, Desmond was unable to think rationally.
- This version of the character is exclusive to the continuity of the television series Young Justice and its tie-in comic book series. It is an adaptation of Mark Desmond/Blockbuster. The original character was created by Gardner Fox and Carmine Infantino and first appeared in Detective Comics #345.
- Mark Desmond was voiced by René Auberjonois for the series and by Mark Rolston for the tie-in video game.
- As a human, Mark Desmond has brown hair and blue eyes; as a mutate, Blockbuster is bald and has red eyes and grey skin.
- 9 Appearances of Mark Desmond (Earth-16)
- 2 Images featuring Mark Desmond (Earth-16)
- Quotations by or about Mark Desmond (Earth-16)
- Character Gallery: Mark Desmond (Earth-16)