Updated:•
Effect: Tactical and lethal equipment randomizes each round.
There are four structures around the map, each with a unique count of animal skulls from one to four. These numbers represent the order in which you'll need to throw a Combat Axe at the animal hides in the Blodheim Hall on the wall.
In my game, the order was as shown in the four images above: Eidskallen Landing, Core Foundry, Tyr's Foot, Burial Grounds. Meaning the order I need to throw a Combat Axe at the
animal hides when facing 
Vulture Aid is the following:
The number of skulls on each structure is randomized each game, so your order may vary. The important thing to remember is which hides represent which structures.
If you hit the animal hides in the correct order, you'll hear Mister Peeks laugh, and the relic trial portal will spawn in the Blodheim Hall. This relic trial is: Zombies can only die by traps.
Make sure you have at least 10K points going into the trial, as you'll need to spend a lot on trap activations (~10).