Boogeymen mucusium. A creature related to a boogeyman. It is made entirely of mucus or "snot and boogers" hence the term boogeyman or bogeyman or boogerman. This elemental being can control and manipulate slime and mucus, it likes living in cold dark places or up children's noses.
Appearance like nasal mucus, or as a child would put it, "an enormous booger" May have rudimentary arms and feet melting into the ground or a pudding like blob from the waist downwards. Slime elemental.
Abilities as an elemental has full control of mucus. Can glue victims or cocoon them with web like goo, can generate pools of sinking slime that is mucus that acts like quicksand to trap victims. Can change size and shape at will. Can grow by absorbing slime or mucus. Harmless as it just wants to scare children or make them filthy by sliming them.
Has been known to take toys from children only to give them back covered in slime, children have witnessed their favourite teddy being turned into a slime teddy.
Defense against the dark arts like most slime monsters, they hate water and soap. Concentrated blasts of Aguamenti and Skurge can destroy them. For muggles, a child should always keep a bar of soap on them to repel a boogeyman or slime monster. Rated XXXX by the ministry as an elemental.
Example Crud from Winnie the Pooh, Meuka, the mad,mad mucus monkey, the bogey King of the Murkwood pumpkin patch.