by sucking his cock
Since you can play the planets in any order, the third robot could be any of the "boss" creatures on the planets. (see the related questions)
There are robot creatures on Astro Knights island, and you use the Mystical Weapons of Arturus to defeat them on the three planets.
feed it to the robot owl
You complete "The Fall of the Robot"
A team of Hobbit scientist formed a symposium to defeat Nag the giant dragon that was harrasing the Shire. They formed Bionic Robot Overlord Works Sindicate (BROWS). BROWS worked long and hard for many months to build a bionic Hobbit that could defeat the dragon and save the shire. The Robot performed well until it got stuck with its hands in its pockets. Although the dragon collided with the robot in its immovable stance and broke its neck. The Dave Robot was victorious and the Shire was saved! yay the end?!
Nothing. When you defeat the giant robot, you take the Orb back to Arturus and Mordred is left behind in his castle. You receive the island medallion.
The "end of the volcano" is meeting Sir Peleas and fighting the Fearsome Fire beast (a robot dragon). Completing the dragon fight sends you and Sir Peleas back to your spaceship.
The object of Astro Knights is to get into space using the crashed saucer Excalibur. Once there, you travel to three planets inhabited by robot creatures and defeat them. Then you can travel to the lair of the villain to rescue the Princess. (for a complete solution, see the related question)
Sir Peleas is at the lair of the Fearsome Fire Beast, inside the volcano on the Fire Planet. He will give you the Ice Arrow to fight the robot dragon.
armadillo
the weakens of the robot dragon is that they cant take fire out of there mouth or they cant burn things
Once you have defeated all three planets, you can travel to the giant asteroid (x-11 y-84) and enter the portal to confront the Binary Bard. No surprise that it is ex-king Mordred as a half-robot cyborg. Enter his castle and defeat him with the help of the robot owl Merlin. (see the related questions below)