Star Wars d20
basilisk
During the Sith War, four millennia before the rise of the Empire, Mandalorian warriors rode into battle on the backs of Basilisk war droids. Massive mobile weapons platforms, the Basilisks served as loyal allies and faithful mounts for the Mandalorian riders. In fact, Basilisks were attuned to their masters' emotions so that they served almost as an extension of their riders' bodies.

The war droids could operate both in atmosphere and deep space, lifting their rear wings to expose a set of high-boost engines. The droids also featured a pair of laser cannons, a pair of shatter-missile launchers, and set of shockwave generator rods whose plasma burst could rupture a starship's hull. In addition to this formidable weaponry, their heavy forward claws were used to smash through obstacles as well as enemy infantry.

Errata

Size: Gargantuan (6.2 m tall [7.5 m with control receiver], 17.5 m long); Initiative +0 (+4 crew, -4 size); Maneuver +0 (+4 crew, -4 size); Speed 20 m; Maximum Velocity 50 km/h; Defense 16 (-4 size, +10 armor); Heavy laser cannon: Attack bonus +2 (-4 size, +2 crew, +4 fire control); Heavy repeating blaster (2): Attack bonus +0/+0 (-4 size, +2 crew, +6 fire control, -4 multifire) or -2/-2/-2 (-4 size, +2 crew, +6 fire control, -6 autofire)

The Tank Droid can be found in the Ultimate Adversaries Sourcebook p 150 

Errata

Size: Huge (8.5 m tall); Speed: 18 m; Maximum Velocity: 45 km/h

The Hailfire Droid can be found in the Ultimate Adversaries Sourcebook p151

Errata

Size: Huge (7.32 m tall); Speed 38 m; Maximum Velocity: 90 km/h

The Homing Spider Droid can be found in the Ultimate Adversaries Sourcebook. 

Once deployed on a target starship, buzz droids go work disabling the craft. They normally do this either by using plasma cutting torches to inflict damage to the hull, using their drill head and extendable computer probe to invade the ship's computer system (the drill head requires 1 round per 5 points of DR to reach a suitable computer access point), or by making Disable Device checks to sabotage key ship systems (see below). Its tools are designed solely for sabotage, adding a +2 equipment bonus to Disable Device and Computer Use checks against starships (included in the stat block below). When multiple buzz droids land on a target, they typically cooperate (see page 73 of the revised Star Wars Roleplaying Game rulebook) to gain a bonus to their Disable Device or Computer Use attempts. Finally, if they are unable to disable any systems through normal means, buzz droids can use their self-destruct system to damage the target (possibly multiplying the damage by making a Demolitions check).