The Ninjat was a prize for the Pirates vs. Ninjas War
Safiria, the queen of vampires, will transform you into a ninjat in the Safiria's plea quest after you have defeated the sheepyre.
Also the Ninjat pet can be brought from the ninja temple (where you train the ninja class skill). there are multiple ninjats to choose from.
lvl 10 ninjat 300 gold and 6-16 base damage.
lvl 35 ninjat 1000 gold and 10-26 base damage.
lvl 65 ninjat 3000 gold and 12-44 base damage.
lvl 85 ninjat 10,000 gold and 16-56 base damage.
lvl 95 ninjat 40,000 gold and 24-80 base damage.
It attacks with a Cat-ana and deals dark damage and always does 2 hits for both attacks
and has a second attack where the ninjat throws a ninja star that does to hits of wind.