Nemec was a clone trooper, a member of the resistance network established by Clone Captain Rex. He took part in a mission to attack a prisoner transport ship alongside defectors Gregor, Echo, and Fireball, aiming to rescue former Captain Howzer and other clones.

Nemec was created on Kamino, cloned from the human bounty hunter Jango Fett, to serve in the Galactic Republic's clone army during the Clone Wars. After the Clone Wars and the rise of the Galactic Empire in 19 BBY, Nemec joined Rex's Clone Underground.

In 18 BBY, Nemec participated in a raid on an Imperial prisoner transport ship carrying disobedient clones to a facility on Wayland. Alongside Echo, Nemec fought the ship's TK stormtroopers, secured the bridge, and interrogated the transport officer. The officer, however, committed suicide by biting an electro capsule. After gathering data from the ship's databank, Nemec and his team fled upon the arrival of an Imperial Venator-class Star Destroyer, escaping into hyperspace as the transport was destroyed.

Later that year, Nemec joined Samson, Greer, Howzer, and Rex on a mission to Pantora to protect Senators Avi Singh and Riyo Chuchi during a meeting about growing dissatisfaction with Emperor Palpatine and the Empire. Nemec and Rex escorted Senator Singh to the meeting.

Nemec met his end on Teth, where he was shot in the back by the Clone X trooper CX-2 while accompanying Rex, Howzer, and the Bad Batch.

As a clone of Jango Fett, Nemec had black hair, brown eyes, and tan skin, standing at 1.83 meters. He wore standard Phase II clone trooper armor dyed dark green, with a green visor on his helmet. His armor included suspenders connected to his belt and an antenna on his back.