Warner Bros. Games and Turtle Rock Studios has announced that online co-op zombie shooter Back 4 Blood, which has now hit 10 million players, is set to receive its scary-sounding first DLC expansion Tunnels of Terror in April. The first major Back 4 Blood DLC includes new playable Cleaners, exclusive character and weapon skins, and more.

To celebrate the co-op game reaching the 10 million players milestone and becoming the best-selling new IP on consoles in 2021, Back 4 Blood’s Tunnels of Terror DLC is releasing on April 12 across Xbox Series X/S, Xbox One, PS5, PS4, and PC. Owners of Back 4 Blood: Ultimate Edition, Deluxe Edition, and the game’s Annual Pass will be granted access to the DLC at no extra cost. Tunnels of Terror can be purchased separately, too. If just one person from your regular co-op team owns Tunnels of Terror, everyone can also access the new playable content.

Tunnels of Terror adds in the new Ridden Hives co-op activity, which sees players teaming up to explore seven different dungeons containing exclusive loot and rewards as well as a new Ridden Type: Warped Ridden. Warped Ridden Ripper, Shredder, and Urchin (these pesky things will set land mines) will also appear in PvP Swarm mode. Sharice and Heng, two new playable Cleaners seen in the official infographic above, will be added as part of the expansion, too, along with plenty of extras including seven new legendary weapons.

Alongside the Tunnels of Terror DLC release date, a free update adding the extra-difficult No Hope difficulty setting will launch on all platforms. As if zombie-slaying wasn’t hard enough already.