Gabe Newell will be a boss in Crawl

UPDATE 08/05/2015: The Gabe Newell boss, Gaben, is out now via Crawl's latest update.

Other additions include the new Mini Beam Eye Bat monster, which rounds out the Flying Eye evolution chain. There's also a few new weapons (Battle Axe, Magic Flame Bow, Chain Ice Staff and Greater Ice Staff), new spells (Raging Bull and Spirit Bow), a new Crypt level and a Toad Necklace artifact.

For the full list of additions and tweaks, check out Crawl's latest patch notes.

ORIGINAL STORY 02/04/2015: Asymmetrical dungeon-crawler Crawl - a game in which up to five players take turns being the hero while everyone else controls monsters trying to kill them - is adding Gabe Newell as a secret boss monster.

"I've been wanting to animate this for soooo long," said developer Powerhoof's Barney Cumming in a recent blog post. "I've got a few larger monsters too powerful to put in evolve trees, so I'd like to squeeze some into this next update as rare statues like the IRS guy. This has been at the top of my list since the very start."

Initially this was thought to be an April Fools' Day gag, but Cumming clarified in a comment that it actually went up on 2nd April in Powerhoof's home of Melbourne, Australia.

Cumming said he's "pretty sure Gaben will be in [the] next update," though he's not sure when this will be. "He's all implemented, just needs final playtesting/tweaks."

This isn't the first time Powerhoof has added something silly to its otherwise moody dungeon crawler. Last year the developer added in tax agents as a reference to the game's delay due to some bureaucratic red tape. "The consistent tone is something I've been very serious about for Crawl, and with the silly joke gods I was able to hide them all behind special codes, making it so you can have silly ones but you have to specifically 'opt in' or else the tone is unbroken which I think is ideal," Cumming explained. "I'll have a think and see if there is some equivalent for the gag statue monsters."

Crawl is currently out on Steam Early Access for £6.99. Our Chris Donlan found it a little rough around the edges, but remained genuinely excited about its development. "Unlike so many Early Access releases, this should be a fascinating project to keep an eye on: a game that promises real pleasures and puts itself forward with palpable confidence - and, occasionally, seems to be struggling rather nobly with the consequences of its own ingenuity," he wrote in his Crawl Early Access impressions.