NOTE: Credit goes to original owners and authors who created this addon: mrcoolmods and humfras. I just updated the addon to work on wow retail. It still may be buggy due to my inexperience with LUA.

From the original addon posting by mrcoolmods and humfras:

Features

Removes Level Up system message.
Triggers a complete animation whenever you Level Up, showing the stats gained and the new skills available to train.

Usage instructions

Install the mod the same way most other mods are installed.
Enable the mod in the character screen for the characters you want (or all of them !).
To test, create a macro: /run CoolLevelUp.Test(45)
NOTE: 45 is the test level but you can change it to any viable level to do the test. The stat numbers that appear on the test macro are test numbers.
Enjoy.

Warning

This is purely a cosmetic Addon, it does not add any tools or whatever (with the exception, maybe, of the new skills indicator), it's just for fun, so do not start arguing it has no use, because I didn't make it for that. :)

Copyright info

The animation includes musics from Chrono Cross, Fire Emblem 9,Suikoden V and Final Fantasy 6 whose respective copyrights are owned by Squaresoft (now Square-Enix), Intelligent Systems and Konami.

FancyDingAnimation