12. Seahorse
Seahorses are a quite unique animal in the reproductive arena because the females actually impregnate the males. Male seahorses carry up to 1500 babies at a time, depending on the type, for a period of 9 to 11 days. After that, the tiny miniature versions emerge and cling on to the nearest shrub. They are the only animals that have sort-of a role reversal, biologically.