Keepers
Keepers are hopping heads that resemble, and are designed after 
Greed. Fiend Folio adds variants of Keepers based on other Sins, although as of The Spitshine Update only two of them can be encountered.
This page is about Keepers added in Fiend Folio. More information about Keepers in general can be found in the vanilla page.
Desirer
Desirers are Keeper variants based off of 
Envy. Like their counterpart they will hop around randomly but hop towards Isaac if he gets close. Similarly to Envy however, a Desirer will split on death, creating 2 Waning Desirers with 10 HP each that behave identically but hop quicker. These 2 Waning Desirers will each then split into 2 Diminished Desirers with 3 HP each on death which hop even quicker and more frequently.
Seducer
Seducers are Keeper variants based off of 
Lust. They will hop around the room aimlessly and will hop towards Isaac when close to him. With each hop they will slide in the direction they were hopping while leaving a thin trail of red creep, only stopping once they reach a wall, obstacle, or hit Isaac.
Trivia
- There are currently sprites and animations for 2 other unused Keeper variants in the files, being Devourer (Gluttony), Indulger (Pride).
- Sloth's Keeper counterpart, called
Sloth's Head, is recolor of a 
Black Globin's Head rather than a Keeper variant, and can be found in a few rare rooms as a joke enemy. - Desirer and Seducer were added in The Spitshine Update.
- They were originally unused in the initial release of the Reheated update.
Gallery
A Waning Desirer.
A Diminished Desirer.
A Seducer's appearance while sliding.
