If I am not mistaken it is a level 100 magikarp
I havent found anything higher than a level 89 though, but the only thing you can catch in the pond is magikarp so... yea
In The Resort Area
The Resort Area
Your villa is in the resort area
the best Pokemon is a lv100 magikarp
It's a level 100 Magikarp.
you go to the resort area
Yes, you can dig up a waterstone in Pokemon platinum underneath the resort area.
You can't only in Pokemon Platinum unfourtunatly.
you catch banette at the fight area, resort area or survival area
It is a level 100 magikarp.
you can get 52 in the Eterna forest and in the resort area
You get it the first time you go to the resort area.