Gloomy bear was created by Mori Chack a Japanese Graphic Designer. He is famous for his Chax product line, and especially the character Gloomy Bear, a 2m tall, violent, pink bear that eats humans. The design is a contradiction to the overly cute cuddly products generated by the corporate giants like Disney and Sanrio's Hello Kitty characters, and other animation companies. Just because we love bears doesn't mean they will love us in return!
Mori Chack believes that humans and animals are incongruent together and animals are born to be wild by nature. This is expressed most pronouncedly by the Gloomy Bear, which is often shown blood stained and attacking humans. It also has a slightly menacing grimace.