The Kzinti are one of the signature races in Larry Niven's Known Space universe. They first appeared (I believe) in the 1966 short story "The Warriors", from which Wing Commander's 'Iason incident' appears to borrow heavily. Many people are familiar with them for two reasons:
* One of the characters in Niven's most famous book, Ringworld (another Known Space story) was a Kzin.
* Niven adapted another one of his short stories involving the Kzin, "The Soft Weapon", into a Star Trek Animated Series episode called "The Slaver Weapon". The Kzin haven't appeared in any live action 'Trek, but they're referenced in a good deal of tie in material (particularly fandom-related stuff from the seventies).
The "Man Kzin" books you may be familiar with are collections of short stories by different authors that are based around earlier references that the Kzinti and Earth fought several wars (like War World for Pournelle's CoDominium or Worlds of Honor for Weber's Honor Harrington).
There've been ten numbered 'Man Kzin' books (with an eleventh due later this year), two 'best of' collections (Best of All Possible Wars and Houses of the Kzinti) and three novels spun off from various stories (A Darker Geometry, The Children's Hour and Cathouse).
The quality of the stories runs the whole spectrum... and unlike the Kzinti references in older Known Space stories, they're *contemporary* to Wing Commander - with the first Man Kzin Wars book appearing around the time of the original Wing Commander game. Still, if you love space cats, they're the way to go.
Now, to the best of my knowledge no one has actually owned up to 'stealing' the Kzinti for use in Wing Commander - science fiction is certainly full of talking cats... I think the biggest connection anyone's ever made is the similarity between The Warriors and the attack on the TCS Iason.
