If they are human they are Octuplets. If they are dogs they are a Litter.
octuplets
If you mean "What are eight babies born on the same day called?": Octuplets (if born by the same mother)
Eight babies born together are called octuplets
If it is a group of calves born from different mothers than you call them a herd of calves or a group of calves. If it is two calves born at the same time from the same mother than they are twins, just the same as human offspring would be called.
Quadruplets.
only if they come from the same pregnancy.
The citizenship of a baby born on a plane, or on a cruise ship, is the same as that of their parents.
the same as a baby born any other day
Octuplets are eight babies carried in one pregnancy.
they are born the same way other animals are
Baby horses are born in the same way other mammals are born: the mother's womb contracts and the baby is pushed out through the birth canal.
I have the same thing from my mother, I honestly just call him uncle, but he's your baby's great-uncle pretty much