Here's a shot of a mysterious person entering into the main room of the Prison Ship
Here's a shot of the Mystery Man removing something from Frax
Here's Rocket Hog  
Frax also used to be a human in Timeranger.
In 2990, Don (Gluto) was caught in Kuronz Family territory and the Kuronz Family was in the middle of trying to hunt him down. Don/Gluto had been injured however a kind human had offered to help him out by stating that he can give him (Don/Gluto) medicine. Gien had the same name even as a human. Don/Gluto asks him if he can stay over until the manhunt is over with. Gien accepts this offer. Gien had been injured when he went out once because he wouldn't reveal the info in regards to where Don/Gluto was hiding at. Don/Gluto had paid some beings in order to do surgery on Gien/Frax so that it would turn him into a robot so that it would save his life.
Here's a shot of the Alien Surgeon

Here's some shots of the battle Quantum is having with Rocket Hog


Rocket Hog is the one that's sparking up because Quantum punches him right in the chest

Here's a shot of Blade Mode in Powered-Up Mode about to hit Rocket Hog
Quantum performs his Double Slash move with his Blade and it defeats Rocket Hog however Rocket Hog then rips off his patch and grows.
Here's a shot of Quantum calling for his zord
Here's a shot of the Q-Rex attacking Rocket Hog with its Tail
Q-Rex Megazord uses its Max Blizzard (aka the double green laser beam move) in order to put the freeze back on Rocket Hog meaning the Max Blizzard is what defeats Rocket Hog and causes him to be back into a frozen state.
This is the episode in which Mr. Asami gets fatally injured. Rocket Hog is the reason for the injury.
This is also the episode in which Captain Ryuuga reveals himself to Timeranger while he's in the past.