This is how The Lord of Skull Spiders reveals himself goes in The Attack of the Skull Spiders.
[The Autobots and Mane Six ready themselves as six black spears appear]
Twilight Sparkle: What is that thing?
Optimus Prime: Get down!
[The clouds clear and the spears are revealed to be the legs of a giant spider--the Lord of Skull Spiders. The Lord of Skull Spiders then lets out a roar]
Ratchet: The Lord of Skull Spiders. He's so fast, we can't outrun him.
Fluttershy: Now you tell us.
Arcee: That means the Skull Spider Bumblebee found was spying on us the whole time.
Rainbow Dash: It was a trap!