ok i got one
AtomicStryker's Infernal Mobs - the next step 1.4,4/ 1.4.5
http://www.minecraftforum.net/topic/1325911-144145-atomicstrykers-infernal-mobs-the-next-step/
adds:
"This mod randomly imbues spawning Living Things in the World with Diablo-style random Enchantments, making them much harder and much more rewarding to kill.
They also drop the quadruple amount of xp and a random enchanted item."
his site
http://www.atomicstryker.net/
his legal stuff
"Regarding Mod Packs:
Here are the general guide lines you need to meet if you want me to allow you to redistribute any of my mods in your modpack. If you do not meet those, do not even bother writing me a PM:
1. at least one mod of the modpack needs to be of your own making. This is to stop the stream of modpack kiddies just cobbling random mods together, having no idea what they are doing.
2. there must be credit and a link to the mod's thread on minecraftforums or this website
3. the modpack may not be used to generate revenue of any kind (eg adfly)
If you do meet those conditions, you may write me a PM on minecraftforums, asking politely for permission. I have not turned down anyone yet who asked nicely"
he has other mods as well