Purple mucus sticks to the hands of anyone who touches it. Take care, as the substance is troublesome to wash off. Beware of pushing strongly on its squishy body, as it makes a mysterious purple fluid ooze out. Its shape and coloration vary, depending on its habitat.
Pokédex entry #422
Shellos in Pokémon GO
It's possible to hatch Shellos from an egg?
No, Shellos can't be hatched.
How many CP would Shellos have after evolving?
If you’ve catched a Shellos and you want to know how many points it would have after evolving, use this evolution calculator and find out easily. You just need to write your Bulbasaur CP and then click “Evolve”.