Magikarp is a medium-sized fish Pokémon with large, heavy reddish-orange scales. It has large, vacant eyes and pink lips. Its pectoral and tail fins are white, but it has a stiff, three-peaked fin on its back and stomach that are both yellow. It also has long barbels. The barbels are white on a female and tan on a male.
A long-lived Magikarp is able to utilize its immense splashing power to leap high enough to scale mountains. It also has a strong enough immune system to survive in the most polluted of waters. However, it is usually overlooked by Trainers because of its perceived weakness: even in the heat of battle it will do nothing but flop around. It is not a strong swimmer, and currents in the water will sweep it downstream. It is normally seen using its former signature move, Splash, to leap out of the water, which makes them easy targets to predators such as Pidgeot.
It is believed that the ancestors of Magikarp were actually much stronger than modern Magikarp, and this led scientists to research this species. Magikarp is found in many bodies of water, such as lakes, rivers, and ponds. However, due to its weak swimming ability it usually lives downstream of the water's flow.