It exists in several finishes (Normal, 1st edition). Each one has its own price; the average above is for the regular version.
Artwork by Ken Sugimori. Some collectors chase every card by the same artist: how to start (in Spanish).
Attacks
Water
Ancestral Memory
Flip a coin. If tails, this attack does nothing. Either way, you can't use this attack again as long as Giovanni's Magikarp stays in play (even putting Giovanni's Magikarp on the Bench won't let you use it again).
WaterColorless
Flail Around
10x
Flip 3 coins. This attack does 10 damage times the number of heads.