For example: someone who was used to draw human porn comics begin working at Marvel, DC, Darkhorse; an animator in Disney which was a furry porn artist; etc...
Can that be possible? Or does he need to come up with different alias and never show himself properly?

i dont think artist who do porn can work for disney and such!......
think about it! no one want that kind of attention and no one will want a porn artist to draw cartoons for their childrens!
so coming up with different alias will be a wise action.

The thing is you are talking about those people who drew porn behind the back of the company and later got fired and some of them got hunormous lawsuits. Trust me you're better off drawing porn and doing commissions.

If you did porn work(Extremely high quality of course) it won't even be a thought to Marvel and DC as they employ quite a lot of artists that opening do a lot of porn work and commissions as well as self made comics. DISNEY however will absolutely deny you the job, or fire you if they find out later, from past artists I'd say they may higher you if you haven't drawn popular porn or seedy stuff in ~5 years to a Decade and your skills and talents are what they are after, however if you drew porn on the side still it is instant firing grounds without pay/severance.

Outside of Disney and maybe nick JR (and other childrens animation stations) though it would not interfere with you getting a job, or even likely get you fired as long as you didn't go gallivanting around about it.

Good threads can't just die.
BUMP

I don't know!!!
Good question though.