What Was the First Animal?

Well, the most reasonable place to look for the answer would be in Genesis.  So let's look at that first. When reading the first few chapters of Genesis, we see that God is creating the world along with the animals. It tells us that the plants were first made(Genesis 1:11), then animals came into the picture. "And God said, “Let the waters swarm with swarms of living creatures, and let birds fly above the earth across the expanse of the heavens'" (Genesis 1:20). The first thing mentioned was creatures that swarm in the depts, then birds were mentioned. Since the creatures in the water were mentioned first, it is likely these creatures were created first. Sadly, the Bible is not specific, but we can assume that the first creature was some sort of fish or some other sea creature.