I made this because I noticed there were not any unicorn add-ons on MCPEDL and thought you might like it so here we are. :)
This Addon has a sword that gives buffs and unicorns that replaces the mule. There is another item called the Unicorn Horn Shard too which is used to craft the sword.
The Unicorn is quite an interesting mob and replaces the mule.
It does not work with other sword addons
The saddle only appears rainbow when equipped on the unicorn so don't think it's on horses. The loot includes leather and unicorn horn shards which replace iron nuggets (No you cannot get shards from iron ingots). The Unicorn also does not take fall damage. You can find them naturally in your world too!
The sword deals high damage and gives you speed, you cannot take fall damage while holding because there is a slow falling effect. Jump boost is enabled when you use this sword so jump like a unicorn!
This requires experimental gameplay
I gave the spawn egg a unique colour/color so it's easy to spot.
The horn of the Unicorn looks much better!
Select version for changelog:
I changed the Unicorn's horn to a better model because before it wasn't quite central.
Enable Experimental Gameplay