Bio
Mechdusa is an early-Hardmode boss exclusive to the Everything Seed (GetFixedBoi/Zenith) which is composed of all three mechanical bosses. It resembles a large serpentine-like creature composed of the three bosses: Skeletron Prime's head is attached to The Destroyer's head with two of its Probes serving as breasts, and The Twins are individually connected via tendrils to Skeletron Prime's eye sockets instead of to each other.

Spawn Conditions

Mechdusa can be summoned manually with Ocram's Razor anywhere at any time. It also has a 1/20 (5%) chance to spawn naturally at dusk (7:30 PM) once a Demon or Crimson Altar has been destroyed, as long as at least one of its constituent bosses has not yet been defeated in the current world. If spawning this way, its arrival is announced by the status message "What a horrible night to have a curse."

Stratigies
• Because the Everything Seed internally advances the world's difficulty by one stage, Mechdusa always drops its components' Treasure Bags in Classic Mode and its relics in Expert Mode.
• This is the only instance of Expert Mode-exclusive items being naturally dropped in a Classic Mode world, and Master Mode-exclusive items being naturally dropped in a Expert Mode world.
• Mechdusa is internally referred to as MechQueen in the game's source code.
• The status message "What a horrible night to have a curse." is likely a reference to the game Castlevania II: Simon's Quest, where the phrase is used to signify the coming of nighttime.
• This is also shared with the Bloody Tear’s tooltip.
• In addition, the method of creating Mechdusa's summoning item, Ocram's Razor, resembles the same method of which the main antagonist of Castlevania II: Simon's Quest, Dracula, is summoned. Both require the collection of body parts to create a whole boss, which is then fought.
• Mechdusa has the highest HP of any enemy in the game, even surpassing the Moon Lord.
• The name of its summoning item, Ocram's Razor, is likely a reference to Occam's Razor, a problem-solving principle which recommends that when given multiple possible hypotheses, one should proceed with the one which requires the least amount of assumptions. It could also be a reference to Ockham's Razor Theatre Company, a British company which combines circus and theater in its productions. It is also likely a reference to the Old-gen Exclusive boss, Ocram.