Captain Tarpals was an NPC, an officer in the Gungan city of Otoh Gunga.
The Phantasmal Malevalence Edit
When Qui-Gon, Obi-Wan, and Jar Jar Binks arrived at Otoh Gunga, Tarpals arrested them because humans weren't allowed in the city. Jar-Jar offered the humans up as food, an idea Tarpals approved of, but Obi-Wan was able to talk Tarpals into taking them to the Gungans' leader, Boss Nass instead.
Sometime later, Qui-Gon along with Obi-Wan, R2-D2, Anakin, Queen Amidala and her whole entourage were gathered at the edge of the river that led to Otoh Gunga, waiting for Jar Jar to return from there. Jar Jar arrived and told them the Gungans had all gone to their secret hiding place in the swamp to manufacture the soap bubbles filled with electric mosquitos that would be used to fight off the Trade Federation invasion of Naboo, that would be lobbed onto the Gungans' dinosaur ponies.
Jar Jar led them to the hiding place, where they met the Gungans headed by Boss Nass and Captain Tarpals. The Queen appealed to the Gungans for aid, but was refused by Nass. She asked Jar Jar to negotiate. Jar Jar told Nass that they should help the Naboo humans defeat the Trade Federation droids, and then they could retrieve the Lost Orb of Phanastacoria. Nass agreed, but Jar Jar insisted he should demand payment for their aid: 10 humans per day so the Gungans would never have to worry about food again. At this point, Padme came forward to reveal that she, Padme Amidala was the real Queen of Naboo. She offered to sacrifice herself to the Gungans to save her people. Fortunately, Anakin came up with a better solution. He pointed out to Nass that without their help, the Gungans couldn't get to the Trade Federation orbital headquarters where the Orb was, and it'd be a shame if someone should destroy the hq and the Orb along with it. Nass backed down, and agreed to help the humans.
Everyone made their strategy. Jar Jar would lead the Gungans to fight the droid army by attacking them with the soap bubbles. Qui-Gon suggested they fill up the bubbles with water from the geysers at high tide. Meanwhile, everyone else would storm the palace through the hangar and take the Fed leaders captive.
Jar Jar took charge of the Gungan army and led them into battle with a rousing speech.
Jar Jar's forces were protected from the Combat Droids' bombardment by a shield that R2 had provided. All Jar Jar and the Gungans had to do was wait for the geysers. Then thousands of droid reinforcements arrived and attacked through a flaw in the shield that R2 hadn't noticed.
At the Gungan/Droid battle, it wasn't going so well for the Gungans.
At the Gungan/Droid battlefield, the Gungans continued fighting until the Feds blew up the moon. Without the moon, there could be no high tide for the geysers being used to fill up the soap bubbles. With their ammunition now depleted, Jar Jar and the Gungans had no choice but to surrender.
While continuing to fight in the orbital hq, R2 realized he could hack into the Feds' systems and deactivate the entire droid army. He did so.
With the droids deactivated, Tarpals admitted he was forced to spy for the Feds because they were threatening his family. Jar Jar told him that as punishment, he wouldn't get to eat the humans along with the rest of the Gungans as they now got ready to invade the capital Theed. Jar Jar then became distracted from his dreams of conquest and cannibalism when he realized that the manes of the Gungans' dinosaur ponies needed grooming.
A New Generation Edit
If Captain Tarpals was still alive and living on Naboo 32 years later, he was most likely killed along with everyone else on Naboo when Darth Vader ordered the planet to be destroyed by the Peace Moon's laser.