I'm trying to keep up with the semi-finalists - in no order: polar bear, lion, gorilla and vampire bat.

is that right?

The tiger would kill the lion, since it is much bigger. Tigers hunt alone wheres lion hunt in group. Lion may not be that efficient in surviving. What's more? Male lions do not hunt. Put me up the list? Tiger please?

Polar bears cannot survive the great heat in a 20c environment. They may not be that accustomed to hunting in that cage. There are stiff hairs on their soles, not only to keep them warm but also to give them friction on ice. These increased friction without ice may hinder it.

Actually, the gorilla is quite strong. Even though it is herbivore, it can keep its predator at bay till it starve out. Because gorillas are so naturally strong, it's been estimated that a silverback male gorilla has the ability to kill a leopard with just one strike from its massive arms.

Grizzilies stand the greatest chance of all. They are omnivorous. One of the strongest and fastest. Bear posesses tremendous power: a large specimen can break a bison's spine with one blow of its powerful forepaw. In spite of their size, some have been clocked at speeds in excess of 35 miles per hour. Aside from their overwhelming strength and deceptive speed, Brown Bears are legendary for their physical stamina. They are capable of running at full speed for miles and miles at a time without stopping. What's more, they are primarily nocturnal. Watch out for this big guy! I am changing my bet from the tiger to the grizzly.

The vampire bat will be shocked and disturbed as soon as it was put in the cage, since it can't handle sunlight resulting in erratic flight. Unless he can survive the sun, he stands no chance. Sense of smell will be rendered useless too by the overpowering odour of decomposing carcassess and animal waste. Bats rely primarily on their sense of smell to find fresh blood. A stinking place prevents the bat from sniffing out fresh blood.

Trogdor in the first round by burnination.

*Awesome guitar solo*