Seawyrm Pygmies were released on May 21, 2011 for Dragon Cave's 5th Anniversary. They were released alongside the Crimson Flare, Dark Myst, Misfit and Nilia pygmies. Like all , their eggs cannot be bitten by Vampire Dragons and they can only breed with other pygmies or Pumpkin Dragons. Under the old Breed sort, these dragons sorted as "Pygmy-Seawyrm" on a user's scroll, between Nilia Pygmies and Pyralspite Dragons. As of August 14, 2016, they now sort using their Encyclopedia name.