Red Devil

Type	Flying Enemy
Environment	The Underworld
AI Type	Bat AI
Damage	50/100/150 (contact); 160320480 (Unholy Trident)
Max Life	600/1200/1800
Defense	40
KB Resist	50%/55%/60%
Banner	Red Devil Banner
Immune to
Coins	1230
Hurt	https://terraria.wiki.gg/wiki/File:NPC_Hit_21.wav
Killed	https://terraria.wiki.gg/wiki/File:NPC_Killed_24.wav
Idle	https://terraria.wiki.gg/wiki/File:Zombie_26.wavhttps://terraria.wiki.gg/wiki/File:Zombie_27.wavhttps://terraria.wiki.gg/wiki/File:Zombie_28.wavhttps://terraria.wiki.gg/wiki/File:Zombie_29.wav

Not to be confused with the pre-Hardmode enemy, the Demon.

The Red Devil is a Hardmode enemy that spawns in The Underworld after any mechanical boss has been defeated. It is considered a more difficult version of the Demon, having more health and dealing much more damage. Similar to the Demon, it drops a magic weapon resembling its means of attack, the Unholy Trident.

While the contact damage of a Red Devil is comparably low, its trident attack is capable of dealing large amounts of damage even to players wearing endgame armor. The tridents are fired in the same burst-like pattern that Demons fire scythes in, although they are slower and move at a constant velocity.

Notes

Red Devils will spawn prior to Hardmode if a mechanical boss is defeated prior to the Wall of Flesh.
In the Getfixedboi and Don't dig up Secret world seeds, Red Devils will drop the Flower of Fire instead of the Unholy Trident.

Tips

Due to their relatively low knockback resistance, they can be easily stun-locked with rapid-fire weapons, such as Megashark or Chain Gun. However, this method still allows them to fire tridents.
Their projectiles are extremely powerful in Master Mode, often being able to kill the player in one or two hits even with high defense.
If close enough, it is recommended to take the contact damage from the Red Devil in order to use the invulnerability to dodge the tridents fired, especially when playing the melee class.

Trivia

The Bestiary entry for the Red Devil: "Conjuring potent spears of dark magic, these elite demons are a serious threat to any who dare enter their abode."