Tygra the greatest Tiger chief

An AU story about Tygra. Tygra grows up as the first born child of chief Javan of the Tiger clan. The tigers are good friends with Thundera. Javan and his wife Sirbriena love their son very much. Tygra has a very happy life. Then that happy life ends. A monster attacks the clan. His parents and the clan start running the monster chases Tygra. Javan rushes to protect his son. As fights the monster Tygra winds up on branch in the side of a cliff. Javan reaches for his son but the branch snaps and Tygra falls. Javan cries fearing his son has died. Tygra survives after falling into a leafy branch of a tree he finds himself in a forest at the foot of the mountain. He can't see his family and friends any where so he goes off to look for them and soon fears the worst. Tygra eventually makes it to Thundera. He was on the streets always hungry then the king and queen take him in as their own. Soon Tygra becomes a big brother. The queen survives the birth and loves her children dearly. But when both Tygra and his brother have grown up Thundera falls because of the betrayal of Grune. His parents go off to help survives. Will Tygra find the home of his birth and his birth family?