This is a fin whale (or Rorqual). It’s the sixth-largest animal on earth, after the blue whale, right whales, and bowhead whale. Unlike those larger whales, the fin whale isn’t lumbering and girthy.
Rorquals were often called the “greyhound of the sea” by whale fishermen due to their slender build and speed when chased; nevertheless, the Antarctic fin whale had over 750,000 animals killed in the 19th and early 20th century, and only about 15,000 remain today. The North Atlantic fin whale is somewhat better off, but never had high populations of individuals to begin with.
Even though fin whales don’t reproduce quickly, they’ve recovered significantly since hunting bans were enacted. For example, the population around Greenland increased by nearly 4,000 individuals between 1974 and 1989, even given Indigenous Subsistence Legislation allowing the Inuit of the country to hunt the whales for food and oil - the skiffs of the Inuit are ill-suited to chase down fast whales, and the total take for the year of 1989 was 4 individuals, 2 of which were already injured and debilitated from unknown causes.
The Principal Forms of the Skeleton and of the Teeth. Dr. Richard Owen, 1854.