Swarmlord

So if he eats Smurfs, does that make him Gargamel?

The Swarmlord, (also known as Schwarmfuhrer) is one of the few Tyranid character with a little bit of personality. The Swarmlord is the supreme general of the Tyranid army, and also the most smart, cunning and experienced Hive Tyrant of the swarm. Wherever the hive fleet could not overwhelm the opposition with sheer numbers or standard tactics, it spawns the Swarmlord, and he gets shit done. And besides being a super-general, the Swarmlord is also a close combat monster and powerful psyker, capable of tearing apart the Despoiler himself.

He's also immortal, as his memories and personality are constantly saved by the hive mind and are placed in brand new shiny body if the previous one got blasted apart with massed melta fire. While the hive mind could potentially spawn a new Swarmlord without the previous one being slain, which could lead to multiple Swarmlords on different battlefields, no evidences of such cloning exists. However, if the Macragge Swarmlord is still alive, hibernating under the surface of the planet, there ARE at least two Swarmlords in the Galaxy.

List of deeds

• First seen on Tyran, leading Hive Fleet Behemoth's final assault on a Mechanicum outpost. Not quite clear why, because the battle was pretty one-sided, although he could have been gathering more data about human warfare.
• Showed up on Macragge and kicked major ass, outclassing Marneus Calgar in both tactics and close combat. He cut off Papa Smurf's limbs, guts and one eye, but due to plot armor, failed to kill him. The honor guard managed to recover their Chapter Master while force-feeding their commander to the Swarmlord to buy some time. While the Ultramarines withdrew to the space, the Swarmlord led his forces to the polar fortresses to omnomnom the First Company and Ultramar PDF. And he succeeded. Unfortunately, the space battle for Macragge hadn't gone so well, mainly because the Imperial Fleet had the balls of steel Ultrasmurfs lacked; while the Tyranids won the planet, they lost the war. It's not quite clear what had happened to the Swarmlord, as his body was never found. It's possible that he's still under the surface of Macragge, waiting for a new hive fleet.
• It's likely that the The Great Beast, who lead Hive Fleet Kraken's invasion on Craftworld Iyanden was the Swarmlord himself. He tricked the Avatar of Khaine into getting shitkicked by twelve Carnifexes, and avoided all Eldar attempts to assassinate him until the corsair prince Yriel finally managed to kill him with a cursed spear.
• Showed leading Hive Fleet Leviathan at the last years of M41, where he once planned end executed massive simultaneous attack on Hodur Sector, resulted in omnomnoming two dozens of imperial worlds (including one space marine chapter home world) in less then two months. Such a rapid and unstoppable Tyranid advance is rumored to be the main reason to force inquisitor Krypman to launch his infamous mass-exterminatus cordon project.
• Now he's rumored to be in the Ontarius empire, pwning Orks. Not much known about his effort there.

On the tabletop

In game the Swarmlord is one of the most deadly and expensive HQs in the game. He can seriously buff his army and kill almost anything in close combat, but is as vulnerable to anti-tank fire as all Tyrants. There are exactly two HQ models outside Apocalypse, capable of killing an unbuffed Swarmlord in a challenge with a chance of better than 50% - Skarbrand and Draigo, but even they would fall beneath The Great Beast, if he buffed himself with the Biomancy powers Iron Arm ad Warp Speed- and considering his four generated powers there is a good chance he would roll both.