Sharga is leader of the Sharkanians, a race of creatures that are related to sharks, just as merfolk are related to fish. He is cunning and tricky, and wants to take over Atlantica.
Sharga appeared in the second episode The Great Sebastian. When King Triton is thinking of making peace with the Sharkanians, he warns his advisor that making peace with said creatures can be very difficult due to them being dangerous where their leader Sharga is cunning and Sebastian must be careful of encountering him where Sebastian must travel to Sharkania to make peace with them in Atlantica.
Meanwhile is Sharkania, Sebastian, Ariel, and Flounder work together to find and talk to Sharga to make peace with his soldiers. Arriving, Ariel, Flounder, and Sebastian follow one of Emperor Sharga's guards to meet their leader. When Sebastian arrives, Sharga talks to him about being hungry despite being on a diet just like Sebastian who tries to offer him crab candy. Too nervous to continue talking with Emperor Sharga, Ariel talks to him abou Sebastian being sent by King Triton to make peace conference with him and the Atlanticans.
Ariel then encourages Sebastian that it is time to do his speech to make peace with Sharga and his soldiers. Sebastian then talks to the emperor about living in peace with the Sharkanians and the Atlanticans. Later, it is then revealed that Emperor Sharga is commanding his minions to use Sebastian to destroy Atlantica. When Sebastian reads the decree given by one of the guards whom Ariel handed to earlier. Later when Sebastian plans to wait for the Sharkanians for them to make peace, one of his minions tells him not to wait in which he explains Emperor Sharga doesn't like waiting.
When Sebastian, Ariel, and Flounder leave Sharkania to go back to Atlantica, two of the Sharkanians plan to signal Sharga's army. Meanwhile, Emperor Sharga then seems King Triton using his trident to repel a Sharkanian whom the thinks he saw an eel where King Triton scares off all the Sharkanians, leaving Sharga defeated as they retreat back to Sharkania.