En route to Sherman's Planet with two robot ships stuffed with quintotriticale, Kirk veers off course to protect Cyrano Jones when a Kilingon ship fires upon his vessel. A skirmish follows, draining the Klingon ship as its new weapon immobilizes the Enterprise. Cyrano carries a tribble predator and a collection of genetically altered "safe" tribbles. The new tribbles don't breed. They just grow fat and large.
Did You Know?
Several times, Scotty is drawn with a captain's extra braid on his sleeves. See more
Tribbles are well known for their proclivities in multiplication.
And they breed fast, too.