The Fabulous Custodes are three members of the Adeptus Custodes that have completely lost their sanity and frequently harass Kitten. They are sometimes known as the Fab-stodes, or the Pillar-stodes, as their character models and names are based on the Pillar Men from Jojo's Bizarre Adventure. Every time they appear, the Pillar Men's theme song Awaken plays.
TTS Canon Edit
As Companions, the Fabulous Custodes served with the Emperor during the Great Crusade and Horus Heresy.
The Fabulous Custodes are extremely hedonistic and obsessed with body oil and massages. While the Custodes nominally have shed their wargear to show that they are in mourning for the Emperor, the Fabulous Custodes use this as a pretext to strip down to their loin clothes and bathe in promethium. And despite being able to physically overpower Kitten, they are also quite unintelligent and ignorant of the politics of the Imperium. They also hate Slaanesh's debauchery despite their obvious hedonism.
The Emperor finds the Custodes to be utterly disgraceful, as they spend more time lubricating their abs (you mean each others' abs) than putting their skills to good use and serving the Imperium at large. He also finds their behavior disturbing, and can't stand to be in their presence.
The Fabulous Custodes managed to steal the position of Emperor's Caretaker from Kitten after they made a deal to help him stop Magnus' rampage (though in the end they were completely ineffectual). They prove to be quite inadequate at the job, however, as none of them are as knowledgeable as Kitten. Furthermore, Karstodes is a complete idiot, Custodisi is inattentive, and Wamuudes is simply creepy.
Two of them, Custodisi and Wamuudes, accidentally discover that there's a safe passage through the Webway gate that leads directly to the Black Library, where they speculate Kitten learned everything he knows. However, they are confronted by Cegorach, who mistakes them for Solitaires. Both of them are too horrified to move, until Ephrael Stern gives them the distraction they need to enter the library and bring back some books for the Emperor - who forces them to listen to him as he reads them out loud.