The grishnar cat was an animal with a fearsome appearance, but which in reality was quite harmless (at least when it was old and toothless), that was possibly native to Qo'noS or another world within the 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")