Someone Added Shadow of Mordor's Nemesis System to Skyrim - IGN - IGN

A modder has put Middle-earth: Shadow of Mordor's genius Nemesis System into Skyrim, which means you can now set yourself up for revenge against dragons (or mudcrabs, or anything else) that kill you.

Syclonix's Shadow of Skyrim: Nemesis and Alternative Death System mod turns almost any enemy that defeats you into a nemesis.

Syclonix notes that Shadow of Skyrim is a "nod" to Shadow of Mordor, rather than a copy of the actual Nemesis system.