Queen Vallnara

Final boss in the Foul Cascade.

She has 2 main abilities.

First - She will drop poison on the ground, easy to dodge. Appears as purple mist.

Secondly - She will impregnate random people in the group, which will stun them for 2 seconds as well as placing a hatchling inside of the target. After 5 seconds, it will burst out as an add.

Tactics
Once the tank engages her have all the healers and DPS move to the little hill with the light on it. Melee DPS should switch to a ranged spec if they have one, since the fight is unfriendly to melee.

The tank will slowly kite the boss in a large circle around the healers and DPS. The tank will need to avoid the purple stuff on the ground, and any melee DPS following him must be especially careful.

Every so often the queen will impregnate someone. They will spawn a new mob which the tank will need to quickly pick up while still kiting the boss. They may then need a cleanse to remove a debuff.

When the tank has 3-4 mobs the DPS should switch from attacking the boss to attacking the adds. AOE dps them down as fast as you can before they overwhealm the healer's ability to keep the tank up. Rinse and repeat.