Marill evolves at Level 23 into azumarill.
On Pokemon Platinum and Diamond versions, Marill evovles at level 21 into Azumarill. I'm not sure what level on Pearl.I know because I have both versions. :)
dratini evovles in to dragonair at level 30 , dragonair evovles into dragonite at level 55
Level 42.
Marill evolves at level 18
Marill evolves into Azumarill at level 18.
Marill evolves into Azumarill at level 18.
Marill will evolve to Azumarill at level 18
it evovles at level 18
40
Marill evolves into Azumarill at level 18.
Marill evolves into azumarill at level 18
Marill evolves at level 18