(Calling it here.)
Carefully, carefully, you think, prodding at the rot with a forepaw. It has some give, but is not overly wet. Faint memories of old dens flit through your mind. Good ground for digging, here. With quick scratches you gouge chunks from the lower curve of this tunnel, sending a spray of orange-green mush up behind you. Several minutes pass. Almost completely beneath the tunnel now, you pause for a moment, sneezing violently to clear a spot of the disgusting goop from your snout. Shaking it off, you continue.
(1d100 → [82] Digging success.
(1d100 → [57] ??
(1d100 → [14] Encounter traveler?)
It takes some time, though you've no real way of judging how much, but you eventually feel the rot give way, crumbling down into an open space. You tumble along with it, rolling to your feet quickly. A glance up shows the winding burrow you've dug twisting up and away from the ceiling of the tunnel you're in now. It looks much the same as the last one, except that you're standing in something of a three-way intersection: one branch leads off to your left, a second down and right, and a third up and to your right rear. Well, there's a fourth branch now, at any rate.
(In order, ~9 o' clock and level, ~2 o' clock and a 30 degree slope downward, ~5 o' clock and a 55 degree slope upward. Your own tunnel is directly overhead.)
[] Take the left-hand path. That's how you get out of mazes, right?
[] Take the right-down path.
You always wanted to be a dwarf.[] Take the right-up path. Maybe there's a surface?
"Ahaha."[] Try to figure out how to leave this place; you got in, so you gotta be able to get out, right?
[] Write-in.