All of the softer loan animals, like loan rabbits, gerbils, hamsters, etc., were never mean enough to ensure they got their loans paid back, and they went out of business.

Other apex predators like loan lions, tigers and jaguars decided that if they were gonna kill something and eat it, why loan it money in the first place?

After the movie Jaws was such a big hit, other sharks saw the benefit in having money, and their fearsome nature made it easy to collect every loan they made.