Skeletron Prime

Terraria · Games · One of the Three Nocturnal Mechanical Menaces, A mechanical part of Cthulhu's skeleton

During the Night

Superhuman Physical Characteristics
Inorganic Physiology (Type 1; Is imbued with Souls of Fright)
Self-Sustenance (All Types)
Large Size (Type 0)
Bodily Weaponry (Via all built-in weapons and head spikes)
Additional Limbs (Has 4 arms)
True Flight
Energy Projection (With Prime laser)
Explosion Manipulation (With Prime cannon)
Berserk Mode (Enrages during daytime, drastically increasing defense and damage)
Enhanced senses (Champion can still be seen by bosses while invisible from invisibility potions)
Non-Physical Interaction (can kill Champion while they are insubstantial from shimmer)
Danmaku
Intangibility (Phasing, can phase through any tile)
Minor Thermal Manipulation (Its presence causes the air around it to get colder)
Mind Manipulation (Immune to Confused, which reverses movement and stops the use of ranged attacks)
Poison Manipulation (Immune to Poisoned)
Durability Negation (Immune to Bleeding debuff, is a machine)

Can only enter berserk mode in daytime

Ranked tied for #1 of 25 in Terraria by strength.

Skeletron Prime vs Ryu (Asura's Wrath) (Street Fighter · Tier HIGH 5-A): Ryu · Slight edge
Skeletron Prime vs Valentine (Guilty Gear · Tier HIGH 5-A): Valentine · Slight edge
Skeletron Prime vs Y'Mera Xebella Challa (DC · Tier HIGH 5-A): Too close to call
Skeletron Prime vs Megaguirus (Godzilla · Tier HIGH 5-A): Too close to call
Skeletron Prime vs Thor (Marvel Cinematic Universe) (Marvel · Tier HIGH 5-A): Too close to call
Skeletron Prime vs Black Shadow (Transformers · Tier HIGH 5-A): Too close to call
Skeletron Prime vs Death Egg Robot (Sonic · Tier HIGH 5-A): Too close to call
Skeletron Prime vs Ra Moon (Mega Man · Tier HIGH 5-A): Too close to call