Magikarp & Wailord-GX is card #SM166 of 248 in SM Black Star Promos (2017), a Promo illustrated by Mitsuhiro Arita. At about $186 it is the #9 most valuable card in the set. It is one of 45 Magikarp cards printed so far.
1999Base Set
2003Skyridge
2006Holon Phantoms
2010HeartGold & SoulSilver
2013Legendary Treasures
2017Crimson Invasion
2018Dragon Majesty
2021Celebrations: Classic Collection

















See the full SM Black Star Promos card list
An ungraded Magikarp & Wailord-GX from SM Black Star Promos sells for about $186. A PSA 10 is worth more, roughly $930 by our estimate, and a PSA 9 around $428.
It is a Promo.
Mitsuhiro Arita drew the art for this card.