Spilefree has the highest base Speed stat of all non-legendary Ghost-type Pokémon, and along with Proboskito, has the highest base Speed stat of all Electric-type Pokémon. It also has the highest base Special Defense of all Electric-type Pokémon.
Before the official release of Clover, the shiny form had golden colored eyes, tail and markings rather than black.
Spilefree is based on a Super Saiyan and a Brazilian making the HUEHUEHUEHUE face. It also has elements of various primates. Judging by its mane and its electric affiliation, it may also be based on the character Blanka from the Street Fighter series.
Spilefree derives from spirit, electric, and free. Coincidentally, the terms spile (a small peg commonly used to hold barrels and similar objects), spill free, and vile can also be derived from its name.