It may not be the toughest critter out there, but it can do some serious damage.
It has a nasty sting your enemies would do well to fear.
All the features you've come to expect in a quality companion critter are present.
You can tell it to follow, stay or go home. (After you've told it where home is.)
There is a summon power, and quest marker to help you find it.
The elytra is Essential
Levels with you
Sneaks when you sneak
Regenerates damaged stats
Slowly heals itself
Catch up teleporting in case it gets stuck far behind you.
Custom combat style, does a better job of blocking.
It's poison sting gets more powerful at higher levels.
When you activate the mod you will be given the summon power.
You must use this spell to call it into the game world the first time.
Since Elytra are Shivering Isles creatures you must have SI installed to run this pluggin.
http://www.tesnexus.com/downloads/file.php?id=30151
http://www.invision.tesalliance.org/forums/index.php?/files/file/353-elytra-companion-critter/