Croagunk will attempt to evolve starting at Level 37.
Level 37
croagunk evovles at level 38 or 37
Croconaw evolves at level 38, not by a stone.
Croagunk will evolve into Toxicroak at level 37.
That's easy, croagunk evolves at level 37-38.
It evolves at level 37.
lvl 34
croagunk evolves at level 37
Croagunk evolves into Toxicroak at level 37.
Rephrase your question = What level does snorlax evolve on Pokemon diamond? =
Croagunk evolves into Toxicroak at level 37