>>46205174All pokemon say their own name, including in game
If you ever look at writing in the pokemon world, you will notice they have their own unique language. Everything we read in the game is just a translation of that language.
This includes pokemon names.
The actual pronunciations in the native tongue are the sounds we hear the pokemon make.
In the show they translate everything for us since it is a dub(japanese is also a dub), hence why magikarp says magikarp and so on.