Daniel was a figure known for his unwavering loyalty to God. He served in a foreign court but still adhered to his religious beliefs. This made him some enemies who plotted against him and got him thrown into the lions' den.
We need more information from the 'Daniel's story' itself. Maybe the story mentions his family, or there could be some clues in the interactions he has with other characters that would reveal his last name, but as it stands, we just don't know.
Daniel was a man who was very faithful to his God. He was living in a foreign land under a different king. But he didn't abandon his religious practices even when it was against the king's orders.
The story of Daniel in the Bible is about his faith and wisdom in the face of various challenges and persecutions. He interpreted dreams and remained steadfast in his beliefs.