Wikipedia tells us this about whales
Whales, derived from Proto-Germanic word hwæl, are a widely distributed and diverse group of fully aquatic marine mammals. They comprise the extant families Cetotheriidae (whose only living member is the pygmy right whale), Balaenopteridae (the rorqual whales), Balaenidae (right whale), Eschrichtiidae (the grey whale), Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales).There are 40 extant species of whales.
But I like whales because they are:
There are some key parts to a whale's anatomy that I think are interesting
This is picture number one
This is picture number two