Buster
Buster is a boss in the Fiend Folio MOD that can appear in the 
Burning Basement.
Behavior
During the fight, Buster's Commission will constantly fly in from the sides of the room and begin orbiting around Buster, up to a maximum of 4.
- Buster's Commission will not catch fire or leave a trail of gunpowder while orbiting, but can still be ignited when flying towards Buster.
Buster will fly towards Isaac, and can perform the following attacks:
- If Buster has 2 or more of his Commission with him, he may release them outwards, where they will stop orbiting him and begin to dart around.
- Eats one of his nearby Commission and begins chewing, slowly flying horizontally until he reaches a wall. Upon reaching it, he will charge to the opposite wall while leaving a trail of fire. Afterwards, he will spit an ignited Commission as a fast projectile towards Isaac, which explodes on impact.
- Moves to either the top or bottom of the room before hopping in place and horizontally charging towards a wall, leaving a trail of fire. He will then whistle and call in 3 of his Commission to the left, right, and center of the room. These fly in vertically from the direction closest to the fire and ignite immediately.
- Releases all of his orbiting Commission, and then charges through a wall and wrapping around to the other side, leaving a trail of fire. He will reappear on the same horizontal level as Isaac.
- If multiple Commission are released and not currently ignited, Buster may blow a raspberry, causing all of his Commission to freeze in place with shocked expressions. Buster will then lob large, fiery projectiles at them one at a time, which burst into a ring of 10 flames on impact and can ignite the Commission.
When Buster dies, he will fall to the ground and begin flashing while causing any of his orbiting Commission to become frozen in place. After a few seconds, Buster will detonate, creating a large explosion which deals 100 damage to all enemies in a large radius.
Notes
- Buster takes reduced damage from the explosions of his Commission.
- Buster is immune to damage from flames such as those from ignited gunpowder, but he is not immune to
Fire Places. - Using the
Defuse card during Buster's death animation will instantly cause him to explode and drop the 
Commissioned Badge.
Spawns
Commission
Buster's Commission are enemies that primarily appear as minions summoned by Buster, but may also show up on their own in rooms across the Burning Basement. They randomly dart around the room in rapid bursts of movement, leaving behind a trail of gunpowder.
When a Commission touches a source of fire, it will become ignited and begin darting around more quickly while leaving small flames behind. After a moment, they will explode and leave a temporary fire behind.
Video Showcase
Trivia
- Some of Buster's sound effects are sampled from the infamous "Nutella Challenge" by JoeysWorldTour.
- If Isaac dies and gets a Game Over against Buster, Buster can be heard taunting Isaac by snickering to himself.
- Buster was voiced by the Fiend Folio developer HappyHead.
- Buster is inspired by the Super Mario enemy Flame Chomp.
Gallery
Buster's appearance while charging.
Buster whistling to summon more of his Commission.
Buster snickering before spitting fiery projectiles at his Commission.
Other appearances of Buster's Commission.
Various appearances of Buster's Commission with bulging eyes.
Drawing of Buster in the Bestiary and on Isaac's last will.
Buster's health bar icon if Enhanced Boss Bars is installed.
Buster as he appeared prior to The Reheated Update.
Placeholder sprite of Buster.
 Bosses 
| |
|---|---|
| Chapter 1 | Buck - Honeydrop - The Whispers - Griddle Horn - Buster - Meltdown |
| Chapter 1.5 | Ghostbuster - Cacamancer |
| Chapter 2 | Battie - Kingpin - Slinger - Monsoon - Aquagob |
| Chapter 3 | The Organization - Gutso the Great - Luncheon - Pollution - Tsar - Junkstrap |
| Chapter 3.5 | Warp Zone - Dusk - Madomme |
| Chapter 4 | Basco - The Sun - Peeping - Cacophobia |
| Chapter 4.5 | Mr. Dead |
| Minibosses | Psion - Gravedigger - Hermit |
| Vanilla Boss Champions | Golden Plum - Ghost Larry Jr. - Mucus Monstro - Technopin - Albino Widow - Beehive Fistula - Possessed Hollow - Wine Husk - Kidney of Infamy - Alien Loki - Fiend Mom - Alien Lokii - Grinch Krampus |