Though he is only identified in the credits as Xandir, the episode "Gay Bash" reveals that his full name is Xandir P. Wifflebottom; it has never been revealed what Xandir's middle initial stands for, if anything. His parents' home resembles a Hobbit-hole, suggesting parody of some contemporary fantasy elements outside video games. Xandir and his parents have pointed ears like Hylians and other elf-like races but their species has not been clearly established.
His special video game move is the "reach-around", which he demonstrates to a bewildered Scorpion from Mortal Kombat, who responds only with the phrase, "Oy vey". He has numerous extra lives, and is constantly earning more; whenever he dies in the show, he usually respawns immediately (the main exceptions being cases where the story requires otherwise, such as many of the main characters dying simultaneously).
In "Gay Bash", when he is trying to commit suicide, he stabs himself 49 times (out of 50), respawning immediately after each death; however, he is talked out of the act before exhausting his last life.
His catchphrases include a very effeminate "Oh my God, oh my God, oh my God!", which he utters while frantically running around in circles, a disgruntled "Oh, f*** me..." and "Strong Xandir, Strong Xandir," which is spoken as he raises his left palm to eye level and tries not to cry.
Unlike the other housemates, whose religions have either been confirmed or strongly hinted at, Xandir's religion is not known. He mentions Jesus in "A Tale of Two Cows" ("Jesus probably loves you"), implying Christian beliefs. However, the subsequent appearance of Jesus (who is seen outside the window shaking his head) and the use of the word "probably" may indicate it is a one-time gag rather than an actual part of his character. In "Foxxy vs. the Board of Education", he has a Christian wedding despite the fact that his marriage partner, Spanky Ham, is a Muslim. In the episode "Wooldoor Sockbat's Giggle-Wiggle Funny Tickle Non-Traditional Progressive Multicultural Roundtable!", Wooldoor Sockbat calls Xandir a "snerd-nurgling Jew"; however, as the line is part of a running gag in which characters make outrageous statements while meaning something entirely different, this information cannot be considered canon either. Additionally, in "Gay Bash", Xandir is shown to be uncircumcised, making it unlikely he is Jewish.
At the beginning of the series, Xandir is dating a woman whom he has apparently known for a long time. After he comes out of the closet in "Gay Bash", his girlfriend breaks up with him in a verbally abusive manner despite being in a very perilous position with presumably no one else to rescue her. Xandir tries to commit suicide, but finds a new purpose in life when he falls in love with a gay genie in a magic lamp (a parody of Robin Williams's character in Aladdin); after the genie is kidnapped by Xandir's nemesis, Lord Slashstab (a parody of Dungeons and Dragons villain Venger), Xandir declares that he is now on a neverending quest to save his boyfriend. The genie is seen again in "Foxxy vs. the Board of Education", where he is one of the guests at Xandir's marriage of convenience, implying that he and Xandir are no longer an item; however, by this point, Xandir has come fully to terms with his sexuality. Indeed, in the very next episode, "Requiem for a Reality Show", while he is advising Toot Braunstein on how to lose weight, Xandir inserts his sword down his throat, much like a sword swallower would. He then notes that he no longer has much of a gag reflex, alluding to his being accustomed to performing fellatio. In "Captain Girl", when Toot uses a black light to look for semen, Xandir's entire body is revealed to be covered with the stuff. In "Xandir and Tim, Sitting in a Tree", Xandir states directly that he has had a lot of gay sex since coming out.
Xandir has had a number of love interests over the course of the show, in addition to his girlfriend and the genie. The two who are mentioned most frequently are men named Craig and Fernando. Craig is a man with whom Xandir had an extremely active sexual relationship, but which ultimately ends because Craig would not come out of the closet. Craig serves as the basis for a running gag on the show; often, after Xandir has made a point of some sort, the scene will cut to him in the confessional saying, "Right, Craig?", or something to that effect. Craig has never appeared on the show in person. Fernando is a Hispanic man for whom Xandir seems to have strong feelings but is unable to convince to settle down. In "Foxxy vs. the Board of Education", he remarks, "Oh Fernando, some day I will tame your wild ways." Xandir often reminisces about various times he and Fernando have had together, usually with a bittersweet air. Fernando's only appearance on the show comes via a confessional segment in "Wooldoor Sockbat's Giggle-Wiggle Funny Tickle Non-Traditional Progressive Multicultural Roundtable!"
Girlfriend aside, he is one of the only housemates who has not been implied to be bisexual, being fully and joyfully gay since his emergence from the closet (though he did once have semi-consensual sex with housemate Toot Braunstein, or as he put it, "tossed (her) a mercy fuck"). He shares a room with Captain Hero, with whom he shares a friendship and many pseudo-sexual discussions—and sometimes more. It is implied that Xandir and Captain Hero have romantic feelings for each other, but Hero's refusal to acknowledge his bisexuality prevents them from having an actual relationship. Xandir implies that he has a very strained relationship with his father in "Terms of Endearment"; he eventually comes out to his parents in "A Very Special Drawn Together Afterschool Special", though they indicate that it was already very obvious to them.
Many of his sexual interests border on the perverse, as he is an aficionado of glory holing, BDSM, role-playing, and even gerbilling. In the first episode, "Hot Tub", we see that both of his nipples are pierced. In "Dirty Pranking No. 2", he wears mascara which stains his face as he cries, and in Season Two, he is shown to wear nail polish. In "Ghostesses in the Slot Machine", he wears makeup, lipstick, and a pink bikini while performing a male strip show in an attempt to seduce The King (who believes Xandir is a woman). The uncensored DVD version of "Captain Girl" reveals that Xandir's penis is pierced.
The idea that Xandir possesses the ability to become pregnant is a running gag on the show. In the episode "Gay Bash", when he locks himself in the bathroom and takes another gay test, Foxxy corrects him, telling Xandir that there's only a pregnancy test in the bathroom. Xandir grumpily replies with, "Oh, great. Now I've got two problems." The joke is repeated in "Unrestrainable Trainable"; when Hero tells Xandir that he always pulls out, Xandir warns him that's not a foolproof method for preventing pregnancy, upon which the scene cuts to Xandir in the confessional breastfeeding a baby and saying, "Right, Craig?"
Xandir largely serves as a vehicle to make fun of gay stereotypes. In addition to the sexual jokes made at his expense (almost all of which come from either Captain Hero or Spanky Ham), it is also revealed that he enjoys knitting, sewing, reading romance novels, and attending ice shows. He also subscribes to the magazines Cosmopolitan, Tiger Beat, Dude'z Health, and Ex-Box Muncher. He is prone to going hysterical when upset. He is the most sensitive and the most emotional of the housemates (though in Season Two, Captain Hero begins to give him some competition in this regard). He is frequently depicted as the most kind-hearted and considerate member of the group. In stories where he is not the focus himself, Xandir is usually cast in the "best friend" role, offering support and advice to one of the others. Of all the housemates, Xandir has shown himself to be the one most willing to go to great lengths to help the others, as exemplified by his marrying Spanky in "Foxxy vs. the Board of Education" so the latter could have health insurance, his having sex with Toot in "A Tale of Two Cows" (even though the idea repulsed him) just to keep her feelings from being hurt, and agreeing to take part in Captain Hero's various crazy schemes, even though many of them result in Xandir being horribly injured.
Additionally, along with Foxy, Xandir is often the most sane or reasonable member of the house. He is frequently dismayed and surprised at the bizarre and illogical tangents the other house mates often take. When asked for advice, his tends to be most grounded in real-world, useful input. Case in point, when Captain Hero was pranking his past self, Xandir was the only one trying to dissuade him, getting worked up, calling him an idiot, and advising him to use his chance to help out his past self.