Crashbug

The Bugmen are a family of four DARK Fiend-type monsters introduced in Generation Force. When the three weaker Bugman cards are assembled in the graveyard, the family's trump card can be special summoned.

Play style
The three level 3 monsters in this family, X, Y, and Z each possess a similar effect; they can all summon another Bugman, so long as a correct Bugman is already on the field when they're normal summoned. Bugman "X" will summon "Z" if "Y" is on the field when it's summoned, "Y" will summon "X" when "Z" is on the field when it is summoned, and "Z" will pull out "Y" if "X" is already on the field when it's summoned.

The trump card of the family, Super Bugman, can Special Summon itself in defense mode by removing X, Y, and Z in your graveyard from play. Not only does Super Bugman have 3000 DEF, the highest of any Level 4 monster, but when it's switched to Attack Position, it's ATK becomes swapped with it's DEF, making it a 3000 ATK monster fast.

Trivia

 * Each of the level 3 Bugman monsters have bombs for heads.