"Crashbug", known as "Bugman" (バグマン Baguman) in the OCG, is a small series of four DARK Fiend monsters introduced in Generation Force and used by Mr. Kay and Caswell Francis in the Yu-Gi-Oh! ZEXAL anime. When the three weaker Crashbug cards are assembled in the Graveyard, the family's trump card can be Special Summoned.
The three Level 3 Monsters in this family, "X", "Y", and "Z" each possess a similar effect to some of the Piece Golems; they each Special Summon another "Crashbug" so long as the other "Crashbug" is already on the Field when they're Normal Summoned. "Crashbug X" Summons "Z" if "Y" is on the Field, "Y" Summons "X" when "Z" is on the Field, and "Z" Summons "Y" if "X" is on the Field.
The trump card of the family, "Super Crashbug", can Special Summon itself in Defense Position by banishing X, Y, and Z from your Graveyard. Not only does "Super Crashbug" have 3000 DEF, the highest of any Level 4 Monster, but when it's switched to Attack Position its ATK becomes swapped with its DEF, making it a 3000 ATK monster. If "Super Crashbug" happens to be in the Graveyard, after it has been summoned properly, you are able to Special Summon him back because he is a Semi-Nomi.
These cards benefit greatly from the use of "Number 34: Terror-Byte" due to its high DEF as well as its summoning requirements. After playing the three "Crashbug" monsters they can be used as "Xyz Materials", providing a powerful monster as well as fuel for a "Super Crashbug" afterward. Another possible Xyz Monster that can be used is "Number 17: Leviathan Dragon", while it will lose its Attack if "Super Crashbug" arrives, it only requires two Level 3 Monsters to Summon and it can become a 3000 Attack Monster while also guaranteeing the ability to detach its Xyz Materials. With "Number 34: Terror-Byte", it will have three possible Crashbugs attached and not be able to lose them because the opponent is not placing any Level 4 or lower Monsters on their Field.
- Each of the Level 3 "Crashbug" monsters have bombs for heads in their OCG artwork.
- Crashbugs "X", "Y", and "Z" appear to be dressed in prisoner-like accessories.
- X - A ball and chain on its neck.
- Y - Hand cuffs on its right hand.
- Z - A striped prison uniform, along with a ball connected to a chain locked to both its ankles.
- This series is similar to that of the "Gadgets", "Piece Golems", Three Musketeers of Face Cards, "Magnet Warriors", and "Reactors"; due to having only 3 members which contribute to the theme's trump card.
- Also, the letters of their names, when placed together alphabetically, form "XYZ", referencing their use to Xyz Summon "Number 34: Terror-Byte".
- When combined with Terror-Byte, this archetype makes a reference to a computer virus. When the virus first appears (Summoning one of them), it infects the system (special summoning the rest of them), then it steals data (taking control of opponent monsters with Terror-Byte), and finally sabotages the system (Super Crashbug switching ATK and DEF of monsters).
- In Japanese, "Bugman" could be a pun to Bomb (爆弾, Bakudan) as they have bombs on their heads and a reference to how when a computer has technical difficulties, it normally means it "has a bug".
- The Crashbugs' fuses are removed in the English card artwork due to the fact that it is a reference to violence, but strangely in the dub, the fuses remain in place.
- All the Level 3 "Crashbug" monsters have the letter in their name on their clothes.