Temperatures become extremely cold.
maybe cause of its surroundings or poision
If the Northern leopard frog were to become extinct it would break the food chain. That would cause a collapse in the ecosystem.
frog eggs ==> tadpole ==> back legs appear ==> young adult frog (tail disappears) ==> adult frog
frog dog snake bug
I'm not sure what you mean about released, but the hoof and frog area should be cleaned regularly to remove rocks and other irritants that would cause the horse to become lame.
Eggs which become tadpoles which become frogs
frog eggs ==> tadpole ==> back legs appear ==> young adult frog (tail disappears) ==> adult frog
Is the frog poisinous? if so then the frog might be eaten and then the bear dies of poison. If the frog wasen't, then I would say the Bear
A leopard frog (sometimes called a meadow frog) is not something you play with (as you might with a dog) - so I would say no.
A frog that has recently left the tadpole stage and has recently become a frog. They sometimes still have the tail on them.
it's environment
It would be dangerous because the frog might not be able to find food or water, and it would die. Or it might have a disease that ends up killing other frogs or animals. It might eat the food that another frog eats resulting in the other frog dieing from starvation. The possibilities are endless.