The "Ugly Man" is a hideous figure and a villain in the TV series Buffy the Vampire Slayer. This monster was based on the traumatic memory of the Kiddy League Coach from his young victim - who was beaten into a coma yet somehow manifested powerful psychic powers that altered reality itself.
The "Ugly Man" was a brutish thug that inspired great fear in his young victim and it was not until Buffy finally convinced the boy to face the monster that he was able to awaken from the coma: suggesting that his fear of the "Ugly Man" was also acting as his prison, trapping him inside a living nightmare.
Due to the "Ugly Man" only existing in dreams it is safe to assume the monster is now gone for good, especially since the Kiddy League Coach has been captured and (presumably) punished for his crimes.
Being a thought-form rather than a physical entity this monster can be considered a variant of the "Tulpa", a spirit said to be created via psychic energy in certain occult circles (in this case the traumatic psychic energies caused by being violently beaten by a much stronger adult male, manifesting itself as a monster).
This is further explored by the fact the Ugly Man has one of his arms replaced with a baseball bat, which it uses to bludgeon victims - this is symbolic of the Kiddy League Coach, who used a baseball bat to beat his young victim into a coma simply for losing a match.