Knights
Knights are roaming enemies characterized by their semi-invincibility with a invulnerable masks and weak point on the back of their head. They walk around aimlessly but charge a bit faster towards Isaac if he crosses their vision.
This page is about Knights added in Fiend Folio. More information about Knights in general can be found in the vanilla page.
Hollow Knight
Hollow Knights are Knight variants with removed brains that orbit the body instead. They are slower than regular Knights and will only walk towards Isaac when lined up with him. The brain leaves a trail of creep while orbiting, creating a spiraling line as the Knight moves and making it difficult to follow in its wake.
The brain will take 3.5 contact damage if it hits Isaac.
Toxic Knight
Toxic Knights are a variant of Knights crossed with 
Poison Minds that behave as usual but will travel diagonally instead.
Psychoknight
Psychoknights are Knight variants with an eye on the back of their head, which opens shortly after spawning. While their eye is open, if Isaac is directly behind them, Psychoknight will react by having its eyes begin to glow, and its head to begin shaking. If Isaac stays behind them for too long, it will teleport to another position in a cardinal direction a short distance from Isaac while charging at him quickly.
After teleporting, the eye on the back of its head will be closed for a couple seconds, and won't be able to teleport again until the eye re-opens.
Strobila
Strobila are Knight variants crossed with 
Scolex. They charge faster than regular Knights and will release 2 streams of slow-moving projectiles that travel perpendicular to their charge direction while charging.
Gut Knight
Gut Knights are a variant of Knights with what appear to be 
Cyst in place of a brain. Shortly after spawning, they produce a line of 6 projectiles that drags behind them, similar to the effect of 
Akeldama.
These projectiles will not be replaced if destroyed.
Psionic Knight
Psionic Knights are a variant of Knights that will not charge towards Isaac when lined up with him. Instead, they roam around randomly and whenever Isaac crosses directly in front of or behind it, it will fire a 
Brimstone beam from behind and propel itself forward rapidly. The brimstone continues until the Knight hits a wall or obstacle, at which point it becomes dazed for a moment.
Lonely Knight
Lonely Knights are a variant of Knights only found inside Crawl Spaces. They move from side to side along the ground, turning when they hit a wall or entity or reach a pit.
They can generally only be damaged from above through the gap in their heads, making them significantly harder to kill from the side.
Trivia
- Hollow Knight's brain is referred to as "Cortex".
The Sun can spawn Hollow Knights with a unique coloration. They otherwise behave exactly the same.- The name of the Hollow Knight is in fact not a reference to the game Hollow Knight. This is only a coincidence.
- Strobila was originally a part of the cancelled Morbus floor mod and was ported as a part of The Reheated Update.
- Strobila is named after the segmented body of tapeworms.
- Psionic Knight's animation files has a secret animation called hidden, which just shows absolutely nothing.
- There used to be a Knight variant in the files called the Trojan. It was an unholy fusion between a Knight and a Host. It had a Basement Renovater icon, but was never able to be spawned ingame.
- Despite this, the Trojan was too vile to remain in the Mod's files, and had to be purged completely when The Spitshine Update came out.
Gallery
Side views of a Toxic Knight.
Front and back sides of a Psychoknight.
An alerted Psychoknight.
A Psychoknight's appearance with its eye closed.
Front and back sides of a Strobila.
Front and back sides of a Gut Knight.
Front and back sides of a Psionic Knight.
A Psionic Knight firing its brimstone laser.
A stunned Psionic Knight.
Old version of Psionic Knight.
