|Prototype Model Unit XJ-6|
|Age||Unknown (Older than XJ-9)|
|Occupation||Superhero/crime fighter (When awake)|
|Likes||Helping people, saving the world, attention|
|Dislikes||The Cluster, Smytus, not getting all the attention|
|Family|| Nora Wakeman (creator/mother)|
XJ-1, XJ-2 XJ-3, XJ-4, XJ-5 (early prototypes/sisters), XJ-7, XJ-8, XJ-9 (later sisters)
Wisteria Wakeman (aunt)
Glenn Wakeman (cousin)
|Friends||Brad Carbunkle, Tuck Carbunkle|
|Enemies||Smytus, The Cluster|
|First appearance||"Sibling Tsunami"|
|Voiced by:||Candi Milo|
Prototype Model Unit XJ-6 is one of the XJ robots sisters created by Nora Wakeman.
She has green pigtails, quite similar to Jenny's, except straighter, is missing her other arm, a screen-like head with one eye and mouth, which resemble the hospital kind, and three insect-like legs. She is occasionally seen with two eyes.
XJ-6 is often subject to dishonesty, as she gets jealous when things happen to others, especially Jenny, seeing as she is the one saving Tremorton instead of her and her earlier sisters. This has been mostly demonstrated in Turncoats. She is even upset when bad things happen to those other than herself, as shown in Sister Sledgehammer, when she was not the first to be absorbed by the Cluster-possessed Jenny.
Sister Sledgehammer. She had to rescue Jenny from the Cluster, along with the rest of her sisters, but XJ-6 became the third to be absorbed by the Cluster-possessed Jenny (which she questioned "What? I'm not good enough to be absorbed first?") but is later freed.
Escape from Cluster Prime (Brief Cameo)
Labor Day (Brief Cameo)
XJ-6 (to Jenny): "Well, if it isn't Mother's favorite!"
Jenny (to XJ-6): "Alright, XJ-6, who's controlling you?"
XJ-6 (to Jenny): "Oh, why do you want to know? So you can stop it and save the day? Is always XJ-9 the big hero? And what are the rest of us? Chopped leavers?
-XJ-6 expressing her jealously about Jenny in "Turncoats".
- XJ-6's envious personality and design are a reference to the "Green Eyed Monster", mentioned in Shakespeare's quote: "O, beware, my lord, of jealousy; It is the green-ey'd monster, which doth mock..."