Where to Find and Catch Mudsdale
From Pokemon Go Wiki
Mudsdale are found and captured in Nest and Habitat locations.
Nests
Mudsdale Nests are locations that consistently spawn Mudsdale.
Habitats
Mudsdale Habitats are spawn locations where Mudsdale is likely to be encountered, but not guaranteed the way a Nest is.
Additional Tips and Information
Best Nests
If you know a really good nest or any of the nests above is really good, list them here: