Their first arrival was in the once called Green Woods (know known as Mirkwood). The Green Woods where corrupted by Sauron (also known as the necromancer in The Hobbit) along with the despicable "witch-Orcs of Angmar". From the corruption came the evil giant spider called Mirkwood spiders.
These spiders are hostile to all other mobs and players who do not have a positive alignment with Dol Guldur.
Types
Now Mirkwood spiders inhabit the corrupted forests of Mirkwood. They come in several different sizes from small baby spiders to enormous spiders. Do not underestimate them as there is usually more than one. The smallest spiders are extremely fast. The venom of green spiders is poisonous, and the venom of blue ones contains a slowness effect, but the black spiders have no venom effect.
Taming
Mirkwood spiders can be tamed just like a horse (mounting them until they like you). They do not require a saddle to control, however.
Though the spiders cannot jump, they more than make up for that with their ability to climb any vertical surface. The spiders are also not hindered by spider webs or webs of Ungoliant.
The spiders can be attached to leads and tied down to fences if need be.
Drops
Mirkwood spiders can drop string, spider-eyes, and rarely a mystery web. The green variants can be right-clicked on with a glass bottle to collect a Bottle of Poison.