Whales are giant aquatic creatures from Earth and other planets. They're regarded as highly-intelligent, often gregarious creatures, and, along with their Dolphin relatives, make up the mammalian order Cetacea.
One species, the Humpback Whales, have been in contact with an alien civilization before their extinction. In 2286, an alien probe was sent to restore contact with them and almost destroyed the Earth due to a lack of response.
After centuries of being hunted down by Humans on Earth, many whale species were relocated to the peaceful ocean planet Cachalot.
Princess Neri of the People of the Ocean is able to communicate with Earth whales.
There are numerous alien species which resemble and/or are identified as whales.