Treasure: Bags of Holding
Bags of holding have been bothering me for a long while. The obvious advantage to use here is Payload, but it is based on the user's BL. GURPS Powers - The Weird gives us a way to base it on HP instead. Still, to emulate D&D bags of holding, you would need thousands of levels of Payload, because bags described in GURPS Low-Tech have around 3 HP. GURPS Psionic Powers has an enhancement for Warp to make its carrying capacity static. For BL/10 lbs (Payload's default load) it says to use 2 lbs. If you use this static capacity for Payload, then the point cost will be almost the same as when using HP+N (Only to determine Payload, -80%) in combination with HP-based Payload. Still, the inherent item cost for Sorcery items gets out of hand quickly, as you'd have to pay billions for a type III bag of holding at TL 3. This is why only metatronic generator costs are given for types III and IV.
The last C-monster from Monster Manual. The couatl is a winged serpent that is typically benevolent and helpful. Possesses both magical and psionic abilities.
This is a quite simple rooster monster with petrifying bite. Doesn't deal much damage, but if you are unarmored and/or fighting against multiple cockatrices, you should be very careful.
When resting or lying in wait, these creatures are almost impossible to distinguish from common black cloaks (the cloaker’s ivory claws look very much like bone clasps). Only when it unfurls does the horrific nature of the creature become apparent.
My favorite D&D game was heavily reliant on one highly unusual wondrous item from the Dungeon Master's Guide - the Apparatus of the Crab (note that its name is a bit different in the actual book). I was playing loose with the rules and modified the thing heavily. Here's my attempt at bringing this thing to GURPS, using GURPS Vehicles 3e and converting the numbers to 4e.