The Bible doesn't explicitly state a singular "first" animal. The order of creation in Genesis 1 describes God creating different types of creatures on different days:
* Day 5: God created "great sea creatures and every living thing that moves, with which the waters abound, according to their kind, and every winged bird according to its kind."
* Day 6: God created "cattle and creeping things and beasts of the earth, each according to its kind."
Therefore, it's not possible to pinpoint one single animal as the absolute first according to the biblical text. Depending on interpretation, it could be argued that the first animals created were sea creatures or birds.