Whale
Toothed whales eat larger fish or meat and are like big dolphins.  They have sharp teeth and usually have a big forehead.  Inside the big forehead is a chamber to make and direct sounds.  They make all kinds of sounds, including sounds so loud they can shock fish.  They can use echolocation to locate things that they can not see.  Some toothed whales, such as the sperm whale, are almost never called dolphins.  Some of them are always called dolphins.  Others are like dolphins in some ways and like whales in others.