Details about GOLDFISH
Goldfish is a Very Rare Topper.
Toppers are on the roof of your Battle-Car and give your car your own style. These fashionable items can either be animated or static. You can equip them inside the customization window in the topper tab.
To get the Goldfish Topper you can either open a specific crate with a key or trade with other players.
You can search for trade offers with Goldfish here.