In Dan Telfer’s reimagining of Beowulf for Theater Oobleck, a church scribe arrives at the monster Grendel’s underwater lair several years before Beowulf, and together scribe and beast translate the lost Book of Judas. More than just a facile reversal of the original, with Beowulf as blustering warrior and Grendel as misunderstood misfit, this is a kind of comic-mythic cosmology of evil, exploring questions of time, mortality, and what it means to be God’s outcast. Colm O’Reilly, in bathrobe and slippers, is excellent as the title monster, part Caliban, part Kramden.