Aak is a male anthropomorphic cat and a character featured in the Chinese tower defense game, Arknights. He resembles an a-gyō, the more lion or cat-like of the two komainu. This is shown in the background of his Elite 2 art.

Aak is an underground doctor who has been assisting Rhodes Islands' medical team as a researcher. Although his methods may be extreme and questionable, they have proven to be effective. In addition, he occasionally provides field support, utilizing powerful combat stimulants to enhance his allies' performance, albeit with some "side effects."

He is also known for friendly firing your units, and killing those who do not have enough HP to withstand his special.