Make an item OP game.

[ChimeraWarden]

Provides immortality.
P u m p k i n b l o c k

 

[PeacefulPotato]

Does the same thing as pumpkin.
Moon Lord (the boss)

 

[ChimeraWarden]

Death beam doesn’t stop.
H o p p i n g j a c k

 

[Snapshot03]

Hopps from space to the underworld so fast it insta kills

Baby Slime

 

[CantWontDo]

Death beam doesn’t stop.
H o p p i n g j a c k

Wow this would actually be super cool A moon lord fight where you have to keep circling him!

 

[PeacefulPotato]

Baby Slime: Killing it summons a mother slime (yes, this creates an infinite loop)
Mother Slime

 

[Snapshot03]

Creates baby slimes mentioned above, also creating an infinite loop

Lepus (Terraria 3DS)

 

[PeacefulPotato]

Mother slimes do that already...

 

[ChimeraWarden]

When the baby slime is killed, a Mother slime spawns. Then it’ll break into 3 baby slimes, then 3 mother slimes, 9 baby slimes, etc.

 

[Terrariamsrs]

stiks to enemies and then slows them down the more that are on said enemy

slime summon

 

[Rukrio]

i'mma assume you mean the slime staff, so
immobilizes any enemy it attacks, except bosses, who are slowed down and have an increased hitbox size, have any debuffs they applied on you nullified, and thier defense is reduced to 0.

EDIT because i forgot an item: Resonance Scepter from 1.4.1

 

[Snapshot03]

Does damage every tick, and after 5 hits makes a star form and explode doing a massive amount of damge

Nightglow

 

[Rukrio]

you can use it to make fullbright potions, as if you had the game just stop lighting properly and instead you could see everything like it was lit up.

Ammo Box

 

[iKan3]

No longer needs to be placed down/interacted with. Can be carried in the player's inventory to give a 66% chance to not consume ammo.

Ale Tosser

 

[Snapshot03]

Allows for infinite ale and tippsy buff

Dark Lance

 

[Rukrio]

you move at your top speed instantly while holding it out to attack and moving horizontally

Magic Missile

 

[FishyGetsEaten]

It is a magic atomic misleading that destroys th world.

Dye

 

[Etotheipi]

Can be thrown to make whatever it hits dye.

Apple Pie.

 

[Kirby737]

Can be thrown to make whatever it hits dye.

Apple Pie.

Can now be made using Apples. It now grants the Divinely Satisfaction buff for 1 hour, which gives 20 defense, 100% critical strike chance, including minions, 300% melee speed and makes you invincible.

Amphibian Boots.

 

[Snapshot03]

Allows you to also walk on water and swim in water

Flask of Ichor