Asexual Reproduction:
Many simple animals can reproduce asexually through the process of
fission. Fission occurs when the animal simply divides into two, and each half then re-grows whatever organs it needs in order to make itself whole.

A planarian (Phylum Platyhelminthes) can
reproduce asexually through fission. The
animal splits in two, then the anterior half
grows a new tail while the posterior half
grows a new head.
Another form of asexual reproduction that is common in simple animals is
budding. Budding occurs when a “bud” grows on the animal’s side and grows into a smaller, genetically-identical version of the “parent.” When it has become large-enough, the smaller animal breaks free of its “parent” and becomes independent.