Phrase used to express disagreement or displeasement with a statement made by another person. It is used normally within discussions about video games on forums and imageboards.
The phrase originates from the relationship system that forms part of Bioware's title, Dragon Age: Origins, where the aforementioned Morrigan is found as an ally and playable character. This character is known for being quite good-looking, for her ability to shapeshift and for her bizarre opinions on pretty much everything, causing almost every attempt to start a conversation with she getting mad at you and the game displaying "Morrigan Dissaproves"
(general thread about first person shooters)
User 1: i think halo is teh best game evar!!!!1
User 2: Morrigan Disapproves
Morrigan: My mother and I spent good days killing the city wards.
Player: But is your mother a witch?
Morrigan: Oh, don't call her a witch, that is a very ugly word *morrigan disapproves*
The Oath of the International Possum Brotherhood.
While granted, this Didelphidic phrase has existed since time immemorial, it has been popularized in comparatively recent years by the 11th Chapter of the Brotherhood, Possum Lodge, and its most illustrious member Mr. "Red" Green.
Note: It is in fact Possum and not the vagabondish "O-Possum".
Mike Hammer: "Sit down, sit down..."
Enter Red Green Mike Hammer "All rise!"
All: "Quando Omni Flunkus Moritati."
Red Green: "Sit down."
She been though a lot and she the most beautiful and perfect girl u can ever ask for she cares for the people she loves and she awesome in the bed. She would do anything to see u and be with u and she cares and loves her bf and would do anything for so if u get a morrigan keep her