Grishnar cat

From Memory Alpha, the free Star Trek reference

The grishnar cat was an animal with a fearsome appearance, but in reality quite harmless (at least when it is old and toothless) – possibly native to Qo'noS or another world within Klingon Empire.

Prior to attacking Deep Space 9 in 2372, Chancellor Gowron likened Captain Benjamin Sisko's claims of his station's upgraded defenses to a "toothless old grishnar cat", attempting to frighten the Klingons with his roar. (DS9: "The Way of the Warrior")