He is very rich and corrupt and runs a very successful business called Walmart which has a monopoly on all lamp oil, rope, and bomb products. He got rich because of two reasons: 1. He does not take credit and 2. He kills his competition. Normally he is nice but he gets very angry when people ask if he takes credit and he will try to kill them if they do so. He also steals most of the items from Walmart from citizens of Hyrule.
Feud With Zelda and Death
One time Zelda the princess of Hyrule went to Walmart and asked Morshu if he takes credit. This angered Morshu very much but he knew he couldn't kill Zelda so he decided to spread a rumor that she eats snails. Zelda got very angry and went on a killing spree across Hyrule which ended in a battle with Morshu where Morshu was shot in the temple. He tried to fend her off using lamp oil, ropes and bombs but he was still killed leaving Walmart abandoned and it was blown up.