Hmm I’d go against the grain and say puppy. Because they grow into needy dogs. Kids grow up AND they come on holiday with you, can go to nursery etc. My parents are always worried about leaving their dog too long, organising holidays for the dog so that THEY can go on holiday, you have to go walk the dog every day and pick up their shit til they die. With a baby you can sit on your bum if you want, and you only have to be in contact with their poop for a couple of years - and it’s your own baby’s poo so I never found it as repulsive as dog turd.