Bark The Polar Bear first appeared in Sonic the Fighters as a powerful challenger in possession of the yellow Chaos Emerald.  Later appearances include Sonic Jam and Generations.  Additionally, Bark also appeared in the Archie Sonic comics with Bean the Dynamite.

He is a tan polar bear, donning a red beanie hat, green and white scarf, complete with fighting gloves and hiking boots.   He tends to growl habitually and due to their past together, has an innate respect for Fiona Fox.  

He is a formidable opponent and can be tough to beat.