Mech Bosses (Mechanical Bosses)

The name for the trio of bosses (The Twins, Skeletron Prime, and The Destroyer) in the game terraria. Usually fought in hardmode. (After Wall of Flesh is defeated)

You: "I just entered hardmode, who do I fight?"
Friend: "The Mech Bosses (Mechanical Bosses). I suggest fighting The Twins first."
You: "Thanks."