What has been said so far;
"A bugbear is a legendary creature or type of hobgoblin comparable to the bogeyman, bogeyman Budy, bugaboo, and other creatures of folklore, all of which were historically used in some cultures to frighten disobedient children. Its name is derived from a Middle English word "bugge" (a frightening thing), or perhaps the old Welsh word bwg (evil spirit or goblin),  or old Scots "bogill" (goblin), and has cognates in German "bögge" or "böggel-mann" (goblin), and most probably also English "bugaboo" and "bogey-man". In medieval England, the Bugbear was depicted as a creepy bear that lurked in the woods to scare children; it was described in this manner in an English translation of a 1565 Italian play The Buggbear."
Suggestions so far;
Bugge, Bwg, Bogill, Bogge, Buggra, Brugg, Bargan, B'zurban, Broggë, Brobba, Rhorlaar