The Star Wars assassin droid is a mercenary droid that works for the highest bidder. These droids don't have a preference for one side over the other; whichever side offers the highest pay can secure their services—at least until a better offer comes along. LEGO elite assassin droid minifigures are black and have open hands so they can hold a gun in either hand. When you buy one of the Star Wars LEGO sets that includes an elite assassin droid minifigure, you'll also receive a gun along with the minifigure.
LEGO elite assassin droid minifigures have been included in three different Star Wars LEGO sets: 8128 Cad Bane's Speeder, 8015 LEGO Assassin Droids Battle Pack, and 66341 Star Wars 3 in 1 Superpack. The Cad Bane's Speeder set contains one elite assassin droid, and the LEGO droid battle pack contains two. The LEGO Star Wars battle pack also has three regular assassin droids, which are silver instead of black. This set contains a speeder that is 8" long and has two flick-fire missiles.
In addition to the Star Wars assassin droid, the Cad Bane's Speeder set includes four other minifigures: Cad Bane, Shahan Alama, a Senate Commando, and a Senate Commando officer. The speeder included in the set is gray with blue details and measures over 10" long. It has two headlight missiles that can be fired using a trigger and you can fit up to six minifigures inside of the speeder.
The other Star Wars set that includes the elite assassin droid, the Star Wars 3 in 1 Superpack, is actually a collection of three different sets: 8015 Assassin Droids Battle Pack, 8014 Clone Walker Battle Pack, and 8091 Republic Swamp Speeder. Everything that is included in these three sets is also in the 3 in 1 Superpack. The three projects that are included are the Republic swamp speeder, a clone walker, and the same speeder that comes with the LEGO Assassin Droids Battle Pack. There are also a total of fourteen Star Wars minifigures included. When you purchase the Star Wars 3 in 1 Superpack, you'll receive two Clone Wars clone troopers, one Episode III clone trooper, a clone gunner, a clone commander, three assassin droids, two elite assassin droids, Barriss Offee, two battle droids, and a super battle droid.
If you want to add a couple of LEGO elite assassin droid minifigures to your collection, your cheapest option is to buy the 8015 LEGO Assassin Droids Battle Pack, which is only $11.99. However, if you want more ships and minifigures, the Cad Bane Speeder set or the Star Wars 3 in 1 Superpack would be a better choice.
