Toyful Temptations is a looting mod, trapping various containers throughout Skyrim to contain some... "toyful" surprises!
How it works
From now on; Chests & Corpses (incl. modded ones) may contain Keys, Toys and trapped (self equipping) Toys. Yay.
The Chance for this to happen is highly customizable. I've also heard that certain chest & creature types are more likely to contain a Key (Deers for example, they seem to have a fetish for swallowing Keys)