Harley-Davidson Evil Boy is the most recent badass conversion of a 2021 Fat Boy performed by Lithuanian garage Killer Custom.
Custom motorcycles often stand out because of the details, and that's exactly what defines this Harley-Davidson Fat Boy transformation. A handful of carefully chosen modifications turned the iconic cruiser into a much darker machine appropriately named the Evil Boy.
The build comes from Killer Custom, a motorcycle shop based in Lithuania with dozens of custom projects to its credit. While the company is known for bold designs, the Evil Boy stands out thanks to its stealthy appearance, accented by contrasting gold details.
Unlike many custom builds, this project leaves the mechanical side of the motorcycle untouched. The 2021 Harley-Davidson Fat Boy retains its factory Milwaukee-Eight V-twin engine and drivetrain, but its stance has changed dramatically. Lowering kits installed at both ends give the bike a much lower and more aggressive profile.
Much of the original bodywork has been reworked with custom components. Black covers replace many of the stock pieces, including those around the sides, axles, and radiator, eliminating nearly all of the factory chrome that typically defines the Fat Boy.
To further reshape the motorcycle's appearance, Killer Custom added a rear frame spoiler, front-end caps, redesigned fenders, aftermarket mirrors, a modified solo seat, and a custom license plate bracket.
Lighting has also been updated. The shortened rear fender now integrates all of the required LED lighting into a single assembly, while the front receives a custom LED headlight.
Custom Harley-Davidson projects rarely come cheap, but the aftermarket parts used for the Evil Boy total about €3,565, or roughly $4,100 at current exchange rates.
That figure does not include the labor required to complete the build or the custom paintwork, both of which add significantly to the overall cost.
It also excludes the donor motorcycle. A used 2021 Harley-Davidson Fat Boy currently sells for approximately $15,000 to $18,500 in the U.S., depending on mileage, condition, and equipment.
For comparison, a brand-new 2026 Harley-Davidson Fat Boy starts at $22,599 before optional accessories or customization.