Pinkymod/Mythril Slime

The Mythril Slime is a Hardmode fought before defeating any mech boss.

Summoning
The Mythril Slime does not spawn naturally and can only be summoned by using a Resonating Gel.

Behavior
Mythril Slime alternates between one of the following: After performing a series of these attacks, Mythril Slime then drops down to the ground and hops about like a normal slime. Every third hop, it fires a shower of Meteors. It also periodically spawns s, and. After hopping around for a while, it repeats it's pattern. As it's health decreases, it performs it's attacks faster and with more damage.
 * Teleporting to either side of the player and dashing
 * Rapidly pursuing the player(while spawning Mythril Slimelings)
 * Hovering over the player then firing down meteors.
 * When the Mythril Slime is below 50% health 4 meteors will continuously rain down from the sky in a diagonal pattern

Trivia

 * Mythril Slime used to use the Biome Mimic AI until it was given its own unique AI.
 * It was created originally during Terraria 1.1.2 for use by the Slime Army against its enemies.

Bestiary Entry
A Slime gone horribly, horribly wrong. Few history books mention such an event, but those that do refer to the creation of the Mythril Slime as the greatest robotic success and failure at the same time. For good reason. The Slime was created by 1.1.2-era Slime Army engineers are mages. If you know anything about Slimes at that time, they were a bunch of bloodthirsty creatures hellbent on the annihilation of the Terrarian Race as revenge. Lord Pinky herself commissioned the creation of a 'Mechanical Slime' of the finest materials, strong enough to handle a army of men by itself but not stupid enough to charge headfirst into said army. The result wasn't so impressive, but a decade later, some other indie scientists got hold of the plans to Mythril Slime and tried recreating it with modern tech.

Oh, and it worked. But soon, Mythril Slime gained full sentience and fell into an existential crisis of machine proportions. And everyone died, yeah.

So now, we have one rogue Mythril Slime in the wild, running around different islands and murdering everything on it's path, long lost it's sanity. A rather sad tale, but even sadder are all those innocent goblins and slimes that died in the wake of this terror. I have to thank that Terrarian for putting the rogue mech to rest once and for all.