I have had this question on my mind on and off for a while now, as I came into a similar situation before with my monk. How in the world do you handle a burrowing creature that grapples something? It seems like a death sentence the instant that the player gets 5 feet underground in combat. It's not like water where you can just swim back to the surface. And with few exceptions, there aren't really any spells that can hit something underground, or help someone underground to get out.
It depends on the monster but when a larger monster does this, it's reasonable to assume that the earth is still lose and that a PC could walk through it as difficulty terrain or doubled difficult terrain.
I agree with abs1nth. I'd let them dig themselves back out the way they came in as difficult terrain or maybe take their action to do so.
And you all laughed at me for my character concept... Who's laughing now!?!?!
Eck wrote: