Terror Grub [RESIN]
[TERRORGRUB01]

It's big. It has lots of teeth (check inside the mouth - you can count 'em!).
The Terror Grubs detail is excellent (remember those teeth?) and, coming in just 2 parts, it requires almost no preparation prior to final assembly and basing.
Throw in a few Tunnel guards to herd it, and perhaps some Maggot Men or giant maggots for company, and you'll have yourself a disgustingly creepy wormy force to make your adventurers flee from ...