like when you encounter a wild dynamaxed Pokemon in a Max Raid, it doesn't say here on this website what the percentage of finding each Pokemon, and if there is or if it is random.
I hope this question is allowed
Each Pokémon Den pulls from two different possible Raid Boss possibilities. The standard will offer the red light and red menu, while very rarely you will get a thick purple light which indicates the Den has a spawn from the rare table. The following lists do not factor in the Wild Area Events which will often temporarily appear over the main dens. Dens in The Isle of Armor can only be natively accessed by players with the DLC but all players can access the raids online regardless of if they have the Expansion Pass.
Each Pokémon Den pulls from two different possible Raid Boss possibilities. The standard will offer the red light and red menu, while very rarely you will get a thick purple light which indicates the Den has a spawn from the rare table.
The following lists do not factor in the Wild Area Events which will often temporarily appear over the main dens. Dens in The Isle of Armor can only be natively accessed by players with the DLC but all players can access the raids online regardless of if they have the Expansion Pass.
Check my source for the lists.
It's random. Only in purple beam dens can Gigantamax Pokemon spawn (assuming it isn't part of an event), but those too are random.
Hope I helped!