Kuchug was a Pecheneg khan who ruled during the 990s CE. The Nikol'sk Chronicle relates that Kuchug converted to Christianity around the year 990 (most likely as a result of Vladimir the Great's Christianization, whom the Chronicle states that Kuchug "served Vladimir with a pure heart". The name of Kuchug (Modern Turkish: Küçük) means 'little, small' in Turkic. He was preceded as khan by Metiga, and his rule began no earlier than around 988 (but had certainly begun by 991; no exact date can be pinpointed for the beginning of his reign.
References
Kuchug Wikipedia(Text) CC BY-SA