A Cactus-Echidna-GG is a spiky, green thing that lives in the bush. It has the ability to shoop da whoop, just like Dr. Octagonapus.
The Cactus-echidna-GG (here called a Cactus X Echidna X GG) appears in "the Legend of BLAAARGH!" where an army of them appear in the Zany Zoo to set free Nightmare.
In 'the Cactus-echidna-GG' event, Count Grapeula put a mysteriously mysterious Cactus X Echidna X GG on the path so someone can step on it and start bleeding, thus, Count Grapeula sucks the person's blood, making him all-powerful. However, the Cactus X Echidna X GG shoop da whoops the victim before Grapeula can get it.
In 'The Bunny Sisters', a Cactus X Echidna X GG is mistakened for a Green Puffle on Club Penguin Island and is taken to the Pet Shop and put in a cage.
In 'A 40-Year-Old Lad', Nicholas Nority refers to a Cactus X Echidna X GG as a 'spiky grape' in which it may be another grape instead of a Cactus, Echidna or GG.