Along with its high defensive stats, it is also resistant to Poison-type moves, making Clodsire even more adequate for Tera Raids.

Source: https://screenrant.com/best-clodsire-tera-raid-build-pokemon-scarlet-violet/

Azumarill has a glaring weakness to Greninja's Poison-type move Gunk Shot, but if holding a Covert Cloak, Azumarill can avoid being poisoned, and a Water Tera type would even sort out its one weakness in this situation.

Source: https://www.cbr.com/best-scarlet-violet-pokemon-tera-raid-battles/