The father of Yonak was a male Rodian who served as the crime lord of the Son-tuul Pride criminal syndicate prior to the first attack on the Son-tuul Pride in 0 ABY. Yonak was later appointed leader of the Pride after his father's death.
By 0 BBY Yonak's father was the leader of the Son-tuul Pride, a crime syndicate that had been terrorizing the Outer Rim Territories for years. During that year, the Galactic Empire began cracking down on smugglers doing jobs for the Son-tuul Pride. Yonak's father beheaded the smugglers who returned to him with that excuse and stored the heads in a vault as food for his beast.
When a Twi'lek smuggler returned to Yonak's father about his lost cargo, he was threatened by the rodian. Yonak's father showed him the consequences of the other unfortunate smugglers and prepared to killed him. However, he discovered a tracker on the smuggler. That was when the Empire arrived. Led by Darth Vader, a contingent of stormtroopers stormed the Son-tuul Pride base. Yonak's father ran for cover and released his beast on the Imperials. While it distracted Vader, the rodian then leapt at him with his dagger. Vader caught him with the Force and fed him to the beast.