As mentioned above, Grim's Hawan Hive Launcher will make it's debut tomorrow in the games' latest launch.
Here's how it works by which Ubisoft have kindly described the gun prior to the character's availability so you can jump in with ease:
"The launcher shoots projectiles that stick to surfaces. Once a projectile lands, it opens up and deploys a canister onto the floor. Then the canister opens and deploys a swarm of micro air vehicles (aka robotic bees) that hover in the area for a set period of time. If a Defender is caught in the swarm or runs into it, the bees will swarm them and track their location in real time for all the Attackers to see.