A boss is an unverified term used to describe an enemy in the Hungry Shark series that overshadows all other enemies in terms of danger, capabilities and endurance.
Boss are very rare compared to other creatures, and some installments of the Hungry Shark series do not have boss enemies in them at all.
Bosses in the Hungry Shark Trilogy
In the Hungry Shark Trilogy, only one of the three installments do not have a boss: Part One. In Hungry Shark: Part Two, the Giant Crab debuts and is the first boss ever in the series. In Hungry Shark: Part Three, there is a powerful enemy in a wheelchair that moves fast and shoots harpoons. He has his own lair dedicated to him and is one of the most powerful enemies in the game.
Giant Crab in Hungry Shark Evolution
There are four forms of the Giant Crab in Hungry Shark Evolution: the red, green, blue and black varieties. The red crab is the weakest, the green/yellow is the second weakest, the blue is the second strongest and the black is the strongest. After the player defeats the black crab the player will only encounter the black crab on upcoming rounds. These crabs attack with their high-powered pincers, swiping at your shark. The attacks deal damage that is far more powerful than most enemies in Hungry Shark Evolution.
The bosses in Hungry Shark Evolution, the Giant Crabs, although not necessarily inflicting the most damage of all the enemies in the game, are still the strongest enemies in the game since they take multiple hits to destroy unlike most other hostile enemies.
The enemy crab's lair before he was added had a sign that said "Gone for fishing"
More information about the Giant Crab can be found here.
Colossal Squid in Hungry Shark World
The Colossal Squid is a boss in Hungry Shark World. Unlike the Giant Crab, the Colossal Squid only has 1 form. The Collosal Squid can be found in the middle of the Boss Battle Map during certain events. The Colossal Squid attacks in several ways, such as slapping your shark with its tentacles, bringing your sharks into its beak to chew on, and by producing ink to hurt the shark. These attacks can be fatal to the shark, but food is not as scarce in the Boss Battle Map as it is in the Crab Lair.
More information about the Colossal Squid can be found here.