there are none.
fish
there a part of a fish that makes them swim
The ones in pairs are: pelvic fins and pectoral fins.
A reptile?
a fish
I do not know of any mammal (mammals are the only animals to have hair) that has fins (fins are the preserve of fishes), but a sea-lion is an animal that is covered in hair and has "flippers".
2 fins
23 pairs
Every one on Earth went in pairs. We can't list the whole animal kingdom here. Actually it was 7 pairs of clean animals (with 4 hooves) 7 pairs of unclean animals (no hooves) and 2 of each type to have them mate.
Animals that use fins to move are whales, dolphins, sharks, and various types of fish. A fin will generate thrust and propel the animal through the water.
isopod