With all the abilities of both a spider and a ninja, she proved quite dangerous. Often silent, even other villains found her confusing. Uma worked alongside Warlord Kodos, both of them joining Naugus in escaping the Zone of Silence, and both were left helpless in a crystalline state when Naugus' magic wand was destroyed. Abandoned by their master, they were taken to Devil's Gulag for incarceration. They later escaped to menace the Freedom Fighters until both died from exposure to Robotropolis' pollution.
Uma's legacy lives on in the form of her children, the Arachne, an army of spider ninjas who also serve Ixis Naugus. The Arachne have been distinguished as villains due to being entrusted with the Sword of Acorns after it tried to possess Sally. They later used it to open a dimensional warp, freeing Naugus from his imprisonment and killing the Ancient Walkers. Due to Ixis' alliance with Mammoth Mogul, the Arachne came to serve Mogul as well. Along with the Destructix and the two wizards, the Arachne were attacked by the Egg Fleet and imprisoned in the Egg Grape Chamber. As a result of Mogul and Naugus abandoning them to the life draining powers of the Egg Grapes, the Arachne died in the second chamber. As a result, they were not rescued by Dr. Finitevus, who liberated the Destructix to serve as his minions.
As ninjas, Uma Arachnis and her children wield a number of traditional Japanese weapons. Among their arsenals are Sai, Nunchuks, Katana swords, Bo staffs, Shurikens, and bows and arrows. Like Kodos and King Acorn, Uma was originally imbued with the ability to transform into a crystalline version of her Mobian self to increase her abilities in battle as well as granting her protection from the Zone of Silence, but this skill was rendered useless not long after she returned to Mobius Prime.
- Uma Arachnis' origins were somewhat explained in prototype story ideas, in which a ninja order known as "the Strand" was introduced. Protectors of the Source of All, this group was the one from which Uma originated. Later, the Arachne would be taken control of by the Sword of Acorns and join the group in their mother's place, causing the rest of the group to be corrupted as well.
- The Arachne were killed off by the Egg Grape Chamber because the writer of the comics during that time, Ian Flynn, felt that the "spider ninja" villain angle had run its course and that it would be pointless to use it again.