One of Mr. Colicos's most beloved characters is that of Commander Kor, who first made an appearance on the original Star Trek series in the episode entitled "Errand of Mercy". A much older Kor made subsequent appearances in several episodes of Star Trek: Deep Space Nine.
If you have an interest in Klingon culture, there are a few places you will definitely want to check out:
Klingon Imperial Diplomatic
Corps - The ultimate reference to Klingon culture and
Klingon Language Institute - The ultimate reference to the Klingon language
Imperial Klingon TV - An online site dedicated to getting a Klingon Star Trek television series established
K'Mel's Guide to Klingon Cyberspace - One of the most complete pages of Klingon-related links