Due to its lack of screen time, little is known about Seaking. There is not enough known about it to even distinguish it from other Seaking. However, Seaking has proved itself to be quite strong, being able to put up quite a fight before Ash was able to reel it in. According to Ash, it is also reasonably large, although it was not large enough for him to win the Seaking Catching Day.
Seaking was Ash's only Pokémon to be caught in an anime-exclusive Poké Ball variant.
For more information on this Pokémon's species, see Seaking.