It was then altered into the script that aired, and then without his knowing novelized.
Niven
has discussed this in print. He
did know it was to be novelized, and asked to do it himself, but Alan Dean Foster was already contracted to do
all episodes. It's probably also why "The Slaver Weapon" was the 22nd episode to be done, appearing in the final volume, "ST Log Ten", well after the rest of the books. ADF left it till last while the dust settled.
The kzin-like creature in "The Time Trap" adaptation was called a "berikazin", although there are other kzinti encounters added as bonus scenes to various Logs, including M'Ress trying to pass herself off as a kzin on an early mission.
In Niven's book
Playgrounds of the Mind, a collection of short stories, novel excerpts, and commentary, he discusses TAS, and "The Wristwatch Plantation". He mentions that he and Sharman Di Vono were interested in getting the comicstrip story published, either in novel form or as a collection of the newspaper strips. Neither happened. Niven also says the story, as presented in the strip, featured a rush ending because the artist wanted to quit. The book includes a summary of the originally planned ending. (See pages 507-510 of Niven's book for more information.)
I think a large reason there have been no more Kzinti in Trek fiction is not because they don't have the right
"The Captain's Honor" turned its kzinti into the
M'dok at the last minute, IIRC, because Larry Niven was having trouble selling the exclusive RPG rights to "Ringworld" if the kzinti kept popping up in ST.
I believe they do, otherwise there would have been issues with reprinting the Star Trek Log book
Niven's contract covered the novelization and Filmation rights.
the Federation Commander... games
In which they became the
Mirak Star League.
What do Kzin really add to Star Trek that you don't get with the Klingons or Gorn?
Plenty!