Saki is the very first Mechasaur to fight against Getter Robo in the anime. He appears in Episode 1.
After Emperor Gore has already unleashed three Mechasaurs on mankind, he finds out that Getter-Rays were being detected in Japan, he has one of his generals to investigate it. The general shows him a robot has been made using the Getter Rays. Emperor Gore then unleashes Mechasaur Saki to destroy it. Saki appears from the ground after the robot went through testing. Saki starts to Attack the robot and manages to destroy it before it can change into Getter 1, killing the pilot Tatsujin in the process. Emperor Gore contacts the place where the robot was made, Saotome Plant. Emperor Gore tells the creator of the robot, Professor Saotome, to give up the Getter plan, but he refuses. So Emperor Gore commands Saki to destroy the plant. Professor Saotome's daughter, Michiru, tries to fend off Saki by using her jet. During this time, a man named Ryoma goes to get Hayato and Musashi to become the three pilots for Professor's Saotome's other Getter Robot, one that was made for fighting. After forming Getter 1, they fight against Saki. When Saki has them in a hold with his tail, Ryoma uses Getter Beam. However, Emperor Gore has given Saki a Getter defense system, so Saki is immune to the Attack. Ryoma then summons Getter Tomahawk, but Saki knocks them down and uses his Heat Ray. However, The Getter Robo manages to get up and slice part of the tail. But Saki still gets them in a hold and throws them away. Saki then launches his two horns at them, but fortunately, the Getter Robo throws the Getter Tomahawk at him and manage to decapitate the Mechasaur. Finally, Ryoma uses Getter Kick to destroy the decapitated head and the headless body falls down and explodes.
Heat Ray: Saki can fire a heated Ray form his mouth.
Electric Tail: Saki can use his tail to wrap around his opponents and electrocute them.
Horn Launch: Saki can launch the two horns on his head like missiles.