There is no bear on this planet who would stand any chance whatsoever against a fully grown hippo of either gender. A male Grizzly weighing in at 600lbs (270) would fare poorly even against a small female hippo of over 3000 lbs (1500kg).
A hippo would win a fight against a polar bear.
The hippo is larger, stronger, has better offensive powers and a defense that would allow it to last longer in a battle than a polar bear.
Elephant
There's no clear answer, but most experts believe that the elephant would come out on top. After all, they're much bigger than hippos and have a lot more strength. Plus, hippos are very smart and would likely avoid picking a fight with an elephant if they could help it.
If a fight occurred between a hippo and a gorilla it is obvious that a hippo severely outmatches even the largest of gorillas and strongest gorillas. In a fight, a hippo can easily kill a gorilla by either charging through them or using its large mouth to take them out.
Even if a swimming tiger catches up with a hippo, it'll have a tough time winning the fight. Hippos have thick, strong skin that protects them from predators. Plus, their massive body makes them almost impossible to take down. Hippos have the most powerful jaws in the animal kingdom with a bite force of 1,800 psi.
The body of a hippo is a valuable prize in this dry land, and everyone knows it. (intense music) Bull hippos are the only ones that stand their ground against lions. And this bull wants them gone. Two ton hippos are quite capable of killing a lion.
Why tardigrades are so damn tough. It's important to note: Tardigrades are basically indestructible only when they enter a special state called cryptobiosis. In harsh environments, the animals tuck in their legs and expel all moisture from their bodies. In this state, they're called tuns.
Nile crocodiles, lions, and spotted hyenas are known to prey on young hippos. Beyond these, adult hippos are not usually preyed upon by other animals due to their aggression and size. Cases where large lion prides have successfully preyed on adult hippos have been reported, but it is generally rare.
A hippo would win a fight against a crocodile. Although crocodiles are large, powerful creatures, they cannot kill a fully-grown hippo. Hippos are large, round animals that are much taller than crocodiles. The only place they would be vulnerable to attack is their legs.
On land, the bear could possibly win a fight if it managed to flip over a crocodile and attack its underside. However, this fight would not be over quickly: the bear would need to do a lot of damage to finally kill the reptile.
An elephant would beat a bear in a fight. Even though we have granted this hypothetical bear the best features of all the various species, the fact remains that they cannot do enough damage to kill an adult elephant. A fully grown bull elephant would most likely smell or hear a bear coming long before it showed up.
A bear would win a fight against a lion. Bears have the advantage in just about every aspect, from size to offensive capabilities. The only time that a lion would win is if it managed to sneak up and ambush a bear, leaping onto it and biting into its head with such power that it shattered the skill.
If the fight takes place in an open area, then the rhino would likely win due to its greater speed and agility. However, if the fight takes place in water, then the hippo would likely have the advantage due to its greater strength and jaw power.
In an elephant vs hippo fight, the elephant is going to win. Assuming both creatures are fully grown adults, the elephant is just too big for the hippo to handle. Hippos are too smart to pick a fight with an elephant, so they have no idea what it takes to bring one down.
The reason crocs live together somewhat peaceably with hippos is because hippos don't eat meat* and crocs usually understand it's foolhardy to attempt to attack an adult hippo. So, they don't even try. No interest on the hippo side and nearly assured destruction on the croc's side.
It's a tardigrade—the most 'indestructible' animal on Earth. Also called water bears, tardigrades can survive up to 30 years without food, live in volcanoes, and endure the vacuum of space.
The honey badger has been called the world's most fearless animal because it doesn't hesitate to attack animals much larger than itself- even lions and crocodiles! Honey badgers are found in arid grasslands and savannahs and even rainforests.
They are both highly aggressive creatures, so a prolonged fight could be brutal. Even then, the lion would probably come out on top, making up for its relative lack of stamina with sheer power. A lion has a good chance of killing a gorilla in a one-on-one fight. The only thing is that a lion rarely fights alone.
"Lions will not want to put themselves at significant risk of injury in taking on large mammals which can very easily injure them," Watson said by email. "In my experience, lion are known to go for easiest targets—and hippo, elephant, and [adult] giraffe certainly do not fall into this category."