Morrigan is a Witch of the Wilds, a clan of sorceresses who, at one time, terrorized the Korcari Wilds. She is willing to leave her home to become a companion to the Warden. If he is male she can form a romance with him.
Her mother is claimed to be Flemeth, a legendary and fearsome personage that walked the wilds centuries ago, although Morrigan herself is dismissive of these tales. Morrigan dislikes the race of men, yet finds herself strangely intrigued by them. With the outbreak of the war, Morrigan is commanded by Flemeth to join the Grey Wardens in their quest to save Ferelden.
If Morrigan's approval becomes high enough she will tell the Warden about her life in the Wilds. Eventually, she will claim that Flemeth plans to kill her in order to prolong her own life (Note: This will only occur if the Warden successfully manages to give her the Black Grimoire as a gift). To prevent this, Morrigan asks the Warden to kill Flemeth.
At the end, a difficult decision must be made. Most believe that a Grey Warden must die in order to defeat the Archdemon, yet Morrigan offers another option. If a male Grey Warden (a male Warden, Alistair, or Loghain) lays with her, she will conceive a child possessing the taint. This dark ritual will ensure that the the essence of the Archdemon is lured into the unborn child, rather than a Grey Warden. Morrigan believes that the child will survive and posses the soul of an Old God. This ritual, Morrigan claims, is the reason Flemeth rescued the Wardens and the reason Morrigan had to accompany them. If the ritual is refused Morrigan will leave the party immediately. If the ritual proceeds, she will stay for the final battle. Afterwards, Morrigan is not seen by the Warden again.
If you engage in romance with Morrigan, she will give you a ring and at the end of the game, the after `story will say "One night, the Warden was sure she was thinking of him and felt regret". Morrigan is the only character with whom it is impossible to get any semblance of a 'happily ever after' as she will leave the group, regardless of your approval rating with her, immediately after the final battle and will 'never be seen again' save through rumours. Should the character survive the events of the game, he can choose in the epilogue to track down and find Morrigan. Bioware have said that we have not seen the last of Morrigan and will likely be showing in the next instalment of Dragon Age.
Morrigan will get angry sometimes after you have a romantic relationship with both herself and Leliana/Zevran.
Shapeshifter: Spider Shape
Primal: Winter’s Grasp
Spirit: Mind Blast
Entropy: Vulnerability Hex, Disorient, Horror, Drain Life
Morrigan’s early spells open up possibility for future combat dominance. Start out with the Cold chain and get to Cone of Cold and Blizzard as soon as possible. After Mind Blast, best thing is to increase your defense tenfold with Force Field (Because there are will be situations where enemies are concentrating on Morrigan rather than other party members). Then get for Crushing Prison which is a powerful single-target root/damage spell. Build on her Entropy spells also and pick up Sleep, Waking Nightmare, and Death Cloud spells (try combined spells for greater damage). Also keep in mind that you can get Bear Shape at level 8, Flying Swarm at level 10, and Master Shapeshifter at level 12.
Most mages must stay in the rear to be effective but with Morrigan it is not the case. Use her ranged spells early, until your mana is low or the enemy engages in melee, then switch to one of your specialization forms and deal effective melee damage. Even though your spells are more powerful, but it’s a nice luxury to be able to adapt to the ever-changing combat dynamics.
Cheat for Infinite Approval
Speak to the Chantry Mother in Lothering, and ask to her about releasing the caged prisoner. You are then able to use the repeatable INTIMIDATE dialoge option to gain infinite approval from Morrigan. Also you must fail the Dialoge Challenge each time to do this. Alistair must not be in your party when you do this or else he will settle the dispute and you'll be given the key.