Skull Mask is the last of the Independent Black Cross Masked Monsters.
Skull Mask's scheme involved the abduction of several Japanese scientists, but in a way different from other Black Cross warriors up to that point. His main method involved delivering a special record to the houses of these scientists which they are asked to play. When they play the record, they are hypnotised by his words to prepare themselves to go to a party, which they generally dress up for and head out in a specially prepared vehicle while the record itself dissolves. Attending the "party" at a mansion set up by Skull Mask, they participate in the events with others (usually Zolders or the Masked Monster himself in disguise) until they become captured and brought down to a dungeon beneath the mansion, where Skull Mask disguises himself as one of these scientists in order to gain their research for Black Cross usage.
After discovering the bizarre abduction of scientists, the Gorenger decide to take advantage of the scheme: finding a house where the strange record has been delivered, Ooiwa disguises himself as one of the scientists who Skull Mask targeted and is taken away to his mansion and his "party". Although Kirenger is eventually discovered at the bizarre event, he is able to use a signal to notify the Gorenger where he was so they could track him down even after Skull Mask transformed into one of the scientists. In combat, Skull Mask tries to use his coffin, but it is destroyed by an exploding arrow fired by Aorenger. When the team tries to finish him off, however, with Gorenger Storm, Skull Mask hits it right back with his staff, only for Akarenger to hit it again with a flying kick, hitting the back of his head and destroying him.
- Skull Mask is known as a very quirky, entertaining Masked Monster; his personality is strange and cordial and even pleases the Black Cross Fuhrer with who he is.
Modus and Arsenal
Skukl Mask's main combat abilities include a staff with a ribcage on its end; as well as a coffin he uses both for transportation and for increasing his own power.