HELIOS-3E was an IG-86 sentinel droid who operated with the bounty hunter Cad Bane while he worked with the Hutts.
Tag: Assassin Droid D6
SD-K4a Mini Assassin Droid
Tiny, 0.14 meter-wide, six-legged droids, SD-K4a mini-assassin droids manufactured by Baktoid Combat Automata used their speed to avoid blaster fire, and while they did not possess the power of the "parent" assassin droid, however, if they could enter a target's armor, they were capable of killing said target with their sharp legs.
B-1 Assassin Droid
The battle droid assassin was a variation of the B1 battle droid used by the Trade Federation and the Confederacy of Independent Systems over the course of the the Clone Wars.