Super Skull Squad:
Super Skull Squad Theme|VS. Super Skull Squad|Team Skull Battle Theme Remix
Super Skull Squad is a team skull alternate of the Super Pony Squad that made its debuted appearance alongside Super RR Squad in the SPS Pokémon Nessoasis episode of the Arcé'des Island titled "It ain't all Skulls and Rainbows." Where they along with Super RR Squad we're fighting against each other for territorial control on Arcé'des Island. The Squad learn about these 2 alternate squads by the Island's Ground Type Kahuna Terreno.
The Super Skull Squad uses mostly Alolan forms of Gen 5 Pokémon and a few of Gen 3, such as:
Alolan Cofagrigus (Dark/Ghost)
Alolan Garbodor (Poison/Fire)
Alolan Cryogonal (Fire/Ice)
Alolan Glalie (Ice/Poison)
Some members of the group are shown in the episode they're introduced in to use Pokémon such Hippowdons and Gyrados.
Milly Skullelf (Milly Darkelf Alternate) is one of the admins of the group and she uses opposites of her Super Pony Squad counterpart:
Instead of Solgaleo she uses a Mega Houndoom
Instead of Claydol she uses a Orcerial, one of the Nessoasis starter Pokémon that's Dark/Water
And instead of using a Genesect and Mew she uses a very bulky Camerupt and a Ninjask.
Towards the climax of the episode, along with the Super RR Squad, the Hivemon of the area unleashed their rage upon the 2 opposing groups for entering and battling in their territory. The Squad was able to die down the hordes of Hivemon before things got out of control.
In the following episode titled "The Arcé'des Battle Royal and the Legend of the Crystal Steelix", the Super Skull Squad returned for revenge by trying to capture the Crystal Steelix and give it to the Super RR Squad as a truce so they both could work together. The Squad was able to stop the group and take down another one of the admins Pokémon, Skullgineer's (Alternate of Super Pony Squad's Engineer) Alolan Cofagrigus who was fighting against the Crystal Steelix to weaken it.
It's not been said yet who the main leader for the Super Skull Squad is…