I think that u can find it in the dark cave on route 45. cuz i have caught it there.
You can catch a wild marill in the safari zone.
Marril evolves at 23, 18 or 24.
look up marril in the pokedex then press A. the pokedex could locate marril . if that doesnt work then try the safari zone
at lvl 18
Azurill
It is very simple to catch a Marill.You can start searching at Routes:120-121 in the TALL GRASSY AREAS and the little water patches around the Hoenn region.Use any type of pokeball.
If you want to find Marril, you'll have to go to the Safari Zone, because it cannot be found in the wild. Go to the Meadow Zone, then surf on the water. A Marill should be found there.
To evolve Marril you have to get it to level 18.
breed marril/azumarril with the sea incense attached hope this helped!
It evolves to Azumarill at level 18. You just have to level it up to evolve it.
The last pokemon that you show to bill grandfather in marril.
you have to get a marill and a ditto together in the day care and soon you will find and egg there or you can breed a boy and girl marril or azumarril