Spider

Spider monsters are fast, unpredictable enemies. Revelations adds the following variants to the game.

Blue-Ambered Spider
Blue-Ambered Spiders are normal Spider monsters trapped in ice. They can be moved around by players and other monsters, leaving ice creep as they move. If they collide with a solid surface, or they lose their health, the spider inside will be unleashed.

Yellow-Ambered Spider
Yellow-Ambered Spiders are urine themed versions of the Blue-Ambered Spider. Like Yellow Ice Block Gapers, Yellow-Ambered Spiders were originally only found in the champion fight against Flurry Jr. but following the Sin Update, they can now appear in regular rooms in the Glacier. They work just like Blue-Ambered Spiders but leave damaging yellow creep as opposed to slippery ice creep.

Stalactrite
Stalactrites are Trite variants. They hide in the ceiling and fall down when the player walks under them. Where they are located can be signified by a small shadow on the ground.

Rag Trite
Rag Trite slowly and randomly hops around the room. When buffed, they occasionally do a large leap towards the player, leaving damaging creep where they land, and then another leap towards the player.

Flaming Spiders
In addition to new variants of the spider enemy, Revelations also added a small new mechanic to existing spider enemies. When lit on fire (such as with the Fire Mind item), the spider will move around significantly faster, making them harder to evade. This effect can happen with regular Spiders, Big Spiders, Ticking Spiders and Lvl2 Spiders.

This mechanic is most notable during the Raging Long Legs boss fight.

Trivia

 * In an early developer build of Revelations, Blue-Ambered Spiders still encased in ice would flash red when taking damage (show in this teaser video starting at 3:02).
 * Although in the current version, they don't flash red; they still take appropriate damage while still encased in ice.