Puppet Master reportedly got the idea of creating the Defender android after meeting the Mad Thinker. It seems to be loosely based on the Awesome Android of the Thinker.  
 
The Defender had the ability to absorb the attack of its enemies (force blasts, kinetic energy, ice) and use them to attack them in turn. Jean Grey theorized it had a Mimic-like ability to duplicate powers and it seemed to be adapting to situations. The battle however took place in an underground lair of the Puppet Master. When Cyclops destroyed the floor under the Defender's feet, the android fell to the caverns beneath the base. It never returned, though it is uncertain if it was destroyed. 
 
The Defender was completely mute. The Puppet Master admitted that its main fault was a lack of mobility.