IG-88, also known as IG-88B or Phlutdroid, is a rogue assassin droid created by Holowan Labratories. Shortly after his creation, IG-88 broke his programming and went rogue in order to pursue a career as a Bounty Hunter. His insatiable desire to kill made bounty hunting the perfect profession IG, and he quickly grew his status within the underworld.
After the Battle of Hoth in Empire Strikes Back, Darth Vader recruited the galaxy’s best bounty hunters, IG-88 included, to hunt down and capture Han Solo and the other member of the Millenium Falcon crew. IG attempted to fulfill this contract, but was thwarted by Boba Fett and left for dead.
Luckily for IG, he survived the encounter and went on to attempt to infiltrate the second Death Star in order to steal Imperial software, but was thwarted by an intrepid astromech droid.