Day 441: Surprise! Gelatinous Cube of Death!

Day 441:

How the heck did a giant gelatinous cube of death make it into the cavern I’ve been mining?!?

It’s huuuuuge, almost to the ceiling, loud, squishy, and as far as I can tell, unable to climb steps!

I dispatched it, as the old-timers used to say about the cave rats, but I’m baffled. And annoyed. And really in need of a bath to remove this slime.