Mar Tuuk is a Neimoidian Captain that served the Confederacy during the Clone Wars.
Mar Tuuk was a veteran naval officer that lead the Separatist blockade over the Twi'lek homeworld of Ryloth. He was charged by the Foreman of the Techno Union Wat Tambor to command the blockade to thwart any attempt by the Republic to liberate the planet.
Tuuk was a calculating captain and anticipated the Republic's counter attack and ordered four Separatist warships to surround the incoming fleet of the Republic and springing the trap he had laid. The trap was successful and Tuuk reported the win to Tambor via hologram. Although Tambor knew that Anakin Skywalker was leading the fleet and warned Tuuk not to underestimate the Jedi. Tuuk later looked information of Skywalker up and came to respect Skywalker for all his achievements but had no doubt that he could out-think the young Jedi.
After the Republic retreated on the first attack, Mar Tuuk predicted that the Jedi would return with his forces for another try and Tuuk was correct. Anakin made contact with Tuuk stating he was surrendering in exchange for food and medical supplies be delivered to the planet below but Tuuk saw through the ruse. Nothing could have led Tuuk to guess that Anakin was really planning on flying the Jedi Cruiser into a collision course with the Neimoidian flagship. Tuuk ordered all batteries to open fire but failed to destroy the damaged Cruiser.
Mar Tuuk later told a battle droid to take command while he returns but really Tuuk evacuated the flagship in an escape pod before the Cruiser crashed into his ship. The blockade eventually was disbanded and the Republic forces were able to free the planet from the Separatists.