Tiny Tina's Wonderlands

Note: This trophy requires the 1.10 or higher patch installed to unlock correctly.

The side quest "Walk the Stalk", becomes available after completing the main story quest "Emotion of the Ocean" and the trophy will pop once you kill the boss and the Punchfather (AKA Brick) flies off.

Parasite - Fought during the mission "Walk the Stalk":

Parasite has the following attacks:

Mushroom spawn
Zombie spawn
Skeleton spawn
Lifeforce draining beam
Poison field
Fisticuffs
Ice orbs

Parasite is a tough boss but keep your distance and you should be ok. This a 3 stage fight, because Parasite has 3 health bars you need to deplete:

You will either need 1 weapon or spell in each of the above elements or 1 seriously powerful non-elemental weapon. Your companion will act as a decoy most of the time, thus giving you time to whittle away Parasite's health. A decent AoE (Area of Effect) spell will take care of most of the enemies and even put a big dent in Parasite's health, as will any kind of Dark Magic so spam them as soon as they finish charging. Eventually Parasite will die, then you can take the portal back to town and meet up with the Punchfather.