Wide Mouth pokemon
"Instead of flippers, Whelter's fins are more similar to flotation devices, helping them stay afloat without expending energy. They move slowly, filtering water through their mouth to feed."
+Level 40 ->
"The largest fish pokemon, Refhuge is incredibly docile and has gained a reputation for ferrying people and pokemon across wide expanses of water. It's red gills can light up to illuminate their paths, creating strange underwater roads at night."
You wanted bigger? How about the biggest living fish? These are a remake of an old pokemon of mine, I know they look quite similar but I love em as they are as they're kinda nostalgic for me.
The evo is based on boats and cars.