From Valve:
This is the one fest where you want to run TOWARD the monsters: Steam's Creature Collector Fest!
From May 12th - May 19th at 10am Pacific you'll find deals on all kinds of games that feature fantastical creatures and monsters, like the ones we're sharing in our official trailer. Don't fear them; collect and tame them!
See you Monday for a full week of Creature Collector Fest on Steam!