A possible solution was raised as I asked such questions to a group of enablers, who took the question in stride. "Why not have both?" they queried. "Have the angler fish body end in bloody entrails--like they're stepping out of its guts." THIS IS WHY I PESTER PEOPLE WITH MY HALLOWEEN PLANS!! Because genius solutions often come from unexpected places. So I'm going to explore this option. I like the idea of making them push through a curtain of fish intestines. It definitely pushes my gross boundaries, but I'm less concerned about those this year than I usually am.
Another option (again from a different source) offered up the possibility of simplifiying the angler fish mouth, but lengthening it and covering the trellis with a tarp.
I definitely like the tunnel idea--much more terrifying to go through a dark place, though I'd still like to spend some time on the mouth to make it as terrifying as possible--cause that's really what scares the bejesus out of me about the whole anglerfish.
I've also been starting to do some research on anglerfish looking for ideas. (Didja know?) There are ~150 different species, and all with weird little deviations. Some are really small (18"), but super vicious looking, while some of the larger ones (5') are a bit dopey. The teeth vary too, which is one of the things I really want to get right--I want them to look terrifying and sharp. Found a good shot of one in a book--I like the varying sizes of teeth, and that the dye that was injected into the fish makes them stand out from the other muscles. The teeth are translucent, but I'm thinking I'll go with just white, perhaps tinged with blood...