Klingon officer who tried to prevent the Federation from obtaining mining rights on the planet Capella IV in 2267.
Kras supported the Capellan Maab's revolt against the Teer Akaar in hopes the new leader would award the Klingon Empire the rights to mine the rare mineral topaline found on Capella.
Kras in turn betrayed Maab and was killed for his actions. (Friday's Child [TOS])
NOTES: Kras was never called by a specific name in the episode and was simply referred to as "Klingon."