This Pokémon’s favorite food is anything that is repugnantly filthy. In dirty towns where people think nothing of throwing away litter on the streets, Muk are certain to gather. A toxic fluid seeps from its body. The fluid instantly kills plants and trees on contact. They love to gather in smelly areas where sludge accumulates, making the stench around them worse.
Pokédex entry #89
muk in Pokémon GO
It's possible to hatch muk from an egg?
No, muk can't be hatched.
Which are muk’s strengths and weaknesses?
muk is a poison type Pokémon. poison type pokémons are strong against grass, bug, fairy pokémons but weak against poison, ground, rock, ghost pokémons. They are not affected by steel type pokémons.