Jolteon is a Fennec Fox-like Pokémon with a very short tail, surrounded by a fringe of spikes on its rear, and yellow fur that has the sharpness of needles (Glaceon shares this same trait, but it's not as obvious). Jolteon also has a white, spiky collar, and pink paw pads.
Jolteon are sensitive Pokémon and easily become sad or angry. Every time its mood changes, it charges power. If startled or angered, it can shoot out bristles that are sharp enough to pierce opponents. Every hair on its body starts to stand sharply on end if it becomes charged with electricity, and the negatively charged ions in its fur create a constant sparking noise. Its fur also stands on end if it is angry or startled.