A mob which transmits signals to the warden

A new mob which can transmit a signal to the warden when they hear a sound. They don't attack the player by them selves but give the warden a better sense of hearing. Killing them in more than one hit causes them to give the player the darkness effect.

This would give the player a side mission while in the deep dark cities and the player would now be in a stealth mission instead of just crouching around skulk sensors. Now the player also has a moving enemy other than just the skulk blocks.