Every boost bar you fill will spawn a drone. Hold your boost to make the drones attack the nearest animal.
The Whale Shark is a Brownish, Blackish, "Fish" in Deeeep.io. It has 4 boosts. It has A.I. Remoras which attack nearby animals. It evolves from the Hammerhead. It is equivalent to the Shark, Killer Whale, Whale, Cachalot, Giant Squid , Polar Bear and Marlin.
To be an effective whale shark it is important to realize your own strength. The whale shark is very strong but against foes like the Giant Squid it needs to be careful. It is very effective at killing slower foes like the Whale, but against faster enemies it's harder for it to get a kill. The main weakness is its speed, however the Remoras (the AI which follow it) provide good attackers for the Whale Shark, and make it a menacing foe.
It's also important to manage the amount of the Remoras that you have; as the amount varies depending on how many boost bars you have full. Holding left click causes the Remoras to attack the nearest animal, and this can provide useful in an escape attempt and for killing an animal.
To combat the whale shark it's imperative to save a boost, just incase you run into one. If you do see one and it attempts to kill you, head for the top of the water and boost in order to get away from it quickly. This is a good strategy as the it can't boost; but you have to be careful not to get stranded on an island, or run into another predator.
Overall, it's a good choice for a final tier animal, and there's no going wrong by choosing it.