Tsukiko (sue-kee-koh)

(a.k.a. Viper/Red/Prime/Beta)

Tsukiko is a red-furred kitsune woman, and also Natsu's mother. She faked her own death during The Age of Coalescence, and remained in hiding ever since, at The Wandering Tavern. She also doubles as a thief wearing a scaled cloak with a large, snake-like hood. She appears in her kitsune form, with nine tails, causing mischief and stealing a wide variety of items. Penguin has been robbed by her repeatedly, including when she took Vecna's Orb and when she rescued her husband Kei.

She is also the leader and founder of Ouroboros, an organization she created in order to aid her in executing the orders given to her by her own daughter Natsu in an alternate timeline. Now that Natsu is a goddess, she is also a member of The Moonlight Covenant.

There are actually multiple versions of her:

Prime, the one who travelled back in time from another reality where Natsu was an ally of Vecna
Beta, the one from this timeline who now has a robotic arm
An unknown number of "simulacrums" they use to do various other important jobs.