The answer is: Whale

Gen 1:21 - The NIV renders this as 'great sea creatures'.

In the account of creation found in Genesis, God's creative power unfolds in a captivating manner, emphasizing the diversity and majesty of life that inhabits our planet, particularly the great sea creatures. When the verse refers to “great sea creatures” or whales, it beckons us to immerse ourselves in the depths of the world's oceans, where these magnificent beings rule the waters.

The Hebrew term used here, “tannin,” can also refer to others with formidable presence in the sea, like crocodiles, hinting at a broader Aquatic realm. However, the whale truly evokes youthful curiosity with its grandeur—some species can reach up to 100 feet long! Imagine the reverence ancient peoples must have had for such creatures, top-notch swimmers of myth and reality alike.

It’s fascinating to note that whales also have profound cultural significance in many civilizations. From the biblical Jonah encountering a “great fish” to the lines of Herman Melville's *Moby Dick*, these marine mammals signify mystery, wonder, and the majesty of God’s creation. Interestingly, there have been more than 80 species of whales identified today, showcasing a remarkable variety of not just form but behavior—some even sing complex songs!

Thus, as we reflect on the creation narrative, let's appreciate not only biblical beauty but also the intricate ecosystems these “great sea creatures” contribute to, connecting their existence to our stewardship of the Earth—a lesson that resonates far beyond just the ancient text.