Tiger Shark
The Tiger Shark is the Tau Empire's fighter-bomber. It is more maneuverable than its Imperial Navy counterpart, the Marauder Bomber, but carries fewer weapons: a twin-linked set of ion cannons, a twin-linked set of wing-mounted missile pods, and burst cannons at the wing-tips. The Tiger Shark's main payload is its fourteen gun drones, mounted in a quick-deployment rack, which can be replaced with a set of six seeker missiles.
Tiger Shark AX-1-0
After their first encounter with the Imperium's Titans during the Damocles Crusade (in which the Tau got their blue asses kicked wherever the Imperium deployed one), it became clear to the Air and Earth Castes that they needed something that could stand up to such massive war machines. To that end, they developed the Tiger Shark AX-1-0 variant, which replaced the ion cannons with fiercely powerful twin-linked heavy railguns (which theretofore had only been mounted on Mantas) and the gun drones with six seeker missiles, with the option to add six more. To make a long story short, it worked. In their first deployment on Taros (as depicted in Imperial Armour Volume Three: The Taros Campaign), a Tiger Shark AX-1-0 first dropped a Warhound Scout Titan's void shields with a missile barrage, and then destroyed it with a blast from the heavy railguns; the Warhound's three fellow Titans decided to withdraw rather than face the same fate.
Fortunately for the Imperium, the AX-1-0 variant is still in its early experimental phase, but given that it is built almost entirely of stock parts (Tiger Shark airframes with Manta weapons), a wider rollout is probable, especially considering the unit's immediate success on Taros. Since the Taros campaign, the AX-1-0 Tiger Shark has proven a valuable psychological weapon for the Tau; the mere possibility that the Tau have a few of these up their sleeve has been successful in forcing the Imperium to be a little more careful about how it deploys its Titans.
And let's not forget that the first time the AX-1-0 was used in the field, it not only killed a Warhound Titan, it also killed the princep controlling it—a one-in-a-million individual with enough willpower to bend an AI (it's an AI even if the Mechanicus call it a "machine spirit", the old farts) to his or her will, making the AX-1-0 an even bigger "fuck you" to the Mechanicus than first thought.
There's also that little bit about a Titan —a giant, expensive war machine that takes decades-to-centuries to build— getting into single combat with a flyer that doesn't take even remotely close to the same amount of time or resources to build and promptly getting its arse unceremoniously kicked.
At least that's how Forgeworld envisioned the fluff to be....until GW decided to fuck over their fluff and have the earth caste changing their whole opinion about bigger-than-Riptide suits to build EVEN BIGGER suits to counter the Imperium's huge walker.
Tiger Shark AX-2-2
Forge World only made a model and rules for this Tiger Shark variant for its Aeronautica Imperialis game. The AX-2-2 replaces the big guns and drone rack with a bay for two Remora Drone Stealth Fighters and the communication equipment required to control them.