you were a human the only human in fact as you were found by Master sheep as a baby as you just showed up on the doorstep of his orphanage kung fu school in a basket wrapped in a bundle with a note that says 'take care of my little Ninja warrior they have a great destiny one day" with your name

As time went by you kept learning under his wing and trained one day after another becoming very skilled as Master sheep taught you everything he knew

One day, Master shifu was coming to the orphanage with Master Oogway and the furious five but you were training in the courtyard too busy to notice as Master sheep was showing them around