A Random Loot Loop is a Loop in which you are likely to find an inordinate amount of loot that you would normally find in a dungeon, but scattered across the planet/plane of existence/etc.
There are two likely causes of such a Loop: One is the typical "It's just the Loop acting up again" response, and the other is that the Stocker known as "Roguelike" is in the Loop. If you think the second is the case then you can try to track him down, but he is very difficult to find.
The usefulness of the equipment in such a Loop varies but it can be anything from "a dusty robe" to a "a spiked javelin of the flora golem" or something like "Toncadira, the Legendary Seeing Plain-looking Pair of Mittens." Books and scrolls such as "The Lantern : What You Wish You Didn't Know" are also common, and sometimes sapient gear, such as "A sapient sling of the acolyte" will spawn, please note that these sapient objects will likely have their own personalities, dreams and desires.
Aside from the occasionally malicious piece of sapient gear there isn't much danger in such a Loop, unless a Loop's resident villain gets ahold of something such as. "a hat of death-breathing."
Random Loot Generator 
MLP Loops 71.1