what you're looking for is a snake. Feed it once a week (less often as they get older), clean up after it once a week, it doesn't need to be taken for walks or need daily brushings.
the food can convienently stay in the freezer, and it doesn't make a mess when it eats.
If you get something like a corn, king or rosy boa the size will stay pretty small. also snakes don't bark, chirp, chitter or meow.
and depending on the snake you can get a few months of no maintenance by brumating it.
any less maintenance and you'd have to get a rock