Hardrock is a Monolith, a centuries old being made of living rock, who guarded his people. He ended up being frozen in suspended animation. As he awoke, he soon joined the Quest team for a while.
- Jonny Quest
- Once the series finished, Hardrock was promptly forgotten and not brought back for future incarnations. The ridiculousness of his addition to the team was poked fun at in the The Real Adventures of Jonny Quest episode Rock of Rages.