The planet was later colonized by humans and the colony was known as Korlon. They later discovered a sentient race of rock-like beings, known as "Dryads", who lived there and were befriended by the colonists.
When Blok first met the Legion he was a member of the League of Super-Assassins. This team was manipulated by the Dark Man, a clone of Tharok, into attacking the Legion. Blok is possibly the last of his people, convinced by Dark Man that the Legion was trying to destroy Dryad, but they were actually trying to save it.
When Blok learned the truth, he turned on the League of Super-Assassins and joined the Legion. Blok had no knowledge of his race; it was not even clear to him whether his form was that of an adult or a child.
- Dryad Physiology: Blok's rock-like body gives him superhuman strength and durability. Blok is a silicon-based life form, not carbon-based; he, and other natives of Dryad, are essentially living rock.
- Superhuman Strength: He is many times stronger than a normal human being, although his strength level is unknown.
- Superhuman Durability: He is far more durable than a normal human, and can probably withstand impacts and pressures that could severely injure or kill a human with no discomfort.
- Telepathic Immunity: He is immune to telepathic attack or possession, as when Esper Lass failed to possess him during the attack of the Legion of Super-Villains.
- Energy Absorption: He is apparently able to absorb energy attacks with no side effects as when Light Lass uses her ability against him, Blok apparently just absorbs the energy, and this includes magical energies like the shadow creatures of Mordru.
- Power Limitation: He can probably be broken, just as a regular rock can, but chances are he is more durable. His massive size also makes him slow and sometimes clumsy. His large fingers also make it difficult to pick objects or use small electronic devices needing small fingers.
- Blok's cousin is the Silver Slasher.
- Blok is also known as Pebble Head.
- 144 Appearances of Blok (Pre-Zero Hour)
- 14 Images featuring Blok (Pre-Zero Hour)
- 3 Quotations by or about Blok (Pre-Zero Hour)
- Character Gallery: Blok (Pre-Zero Hour)
Legion of Super-Heroes member