The Nightmare Gargoyle is a monster conjured by the Trix. It is initially small, but gains a bigger lizardlike appearance as it becomes stronger. It serves as antagonist of the episode The Nightmare Monster.

The Nightmare Gargoyle caused StellaMusa, and Tecna to have nightmares and drained some of their power at the most terrifying moment. Later the Winx fought against the Nightmare Gargoyle, but their attacks only made it bigger. Its objective was to drain everyone else and get to Bloom. When the battle went outside, Faragonda appeared, and together she and Bloom used magic attacks on the gargoyle and destroyed it.