Giovanni also holds down a "legitimate" job as well, as the Gym Leader of the Viridian City Gym. There, trainers can battle him for the Earth Badge, the final badge needed to enter the Pokemon League. The Viridian Gym appears to have a Roman theme, with armored guards and huge marble columns. Giovanni's battle Pokemon include Kingler, Golem, Machamp, and Rhydon. The Boss Rocket seems to enjoy toying with his opponents, lulling them into a false sense of security, then pulverizing them with devastating attacks. When Gary battled him, Giovanni's Kingler was knocked out by Arcanine, then Golem was KO'd by Nidoking. When Gary smugly bragged that Giovanni could never beat him, the Boss Rocket smiled and sent out Mewtwo. Even with Arcanine and Nidoking fighting simultaneously, Gary didn't stand a chance.
Giovanni, like many other super-villains, has a favored pet. Although TR's Meowth used to be "top cat", Giovanni selected a new favorite after Jessie, James, and Meowth failed him several times. When TR reports to their Boss right before the St. Anne scheme, Giovanni is stroking a Persian, announcing that it is his new favorite.
Persian seems to have a smug, haughty attitude, especially toward Meowth. Persian is often given saucers of milk and otherwise pampered by the Boss. In fact, it seems that Persian enjoys a higher status than most of Giovanni's underlings.
Giovanni often communicates with his underlings via a video phone. Occasionally he also contacts his agents over the internet (using their official TR laptops). In early episodes, his face is almost completely obscured by shadow, and his voice is digitally altered. However, in "The Battle of the Badge", we see and hear the real Giovanni for the first time.
Giovanni wanted the world's most powerful Pokemon, so he commissioned his scientists to genetically engineer a super-clone of Mew. Thus Mewtwo was created. When the angry, angsty Mewtwo destroyed the laboratory, Giovanni reasoned that Team Rocket could help the creature control his newfound strength. However, Mewtwo was not content to merely do the bidding of humans, and escaped.
Then (according to Pokemon Live), Giovanni had not given up on his goal to own the world's most powerful Pokemon. He created the mechanical marvel, MechaMew2 (based on the original Mewtwo), a robotic creature that learns and returns each Pokemon attack. To lure trainers to battle him, Giovanni offers the one-of-a-kind Diamond Badge as a reward for defeating him. Naturally, Ash and Pikachu save the day and defeat the mechanical creature.
Unlike Ash-tachi and TR (Jessie, James, and Meowth), Giovanni's memory of Mewtwo had not been erased when the clones flew off to find a new, peaceful home elsewhere. Thus the Boss Rocket still grudgingly remembered Mewtwo's existence, and sought to regain control over the genetic Pokemon. Enlisting the help of Agent 009 Domino, Giovanni located Mewtwo's whereabouts and sent the TR Attack Squad to capture Mewtwo and his cloned friends. Giovanni had built a new device that would contain Mewtwo's energy and sap his will, until the Boss was in complete control of the creature once again. Yet again, Ash and his friends helped to defeat Giovanni's evil plans and Mewtwo was saved. This time, however, Giovanni's memory of Mewtwo was erased for good.
The Boss doesn't just work all the time; after Team Rocket HQ was destroyed, Giovanni takes a short vacation to Seafoam Islands. The Boss also appears to enjoy drinking alcohol (seen with a glass of some unidentified liquid in Mewtwo Returns). Giovanni also seems to have remarkable grip strength: he is able to easily crush a drinking glass, as well as a cellphone/communicator when angered.
Surprisingly, Giovanni can sing. He has several songs in Pokemon Live: "It Will All Be Mine" (the deliciously evil song explaining his plans for world conquest), a sinister reprise of "You and Me and Pokemon", and "You Just Can't Win" (sung by Giovanni and Ash).
According to Pokemon Live, Giovanni and Ash's mom (Delia), used to be very close. Apparently Delia wasn't quite the upstanding woman she is today; in her youth, she used to hang out with a group of troublemakers. One of her friends back then was Giovanni. When she meets him later, he remarks on how much she's changed since he last knew her.
The ongoing rumor about Giovanni is that he is truly Ash Ketchum's father. It is true that (in the anime) Ash and Giovanni have never had a face-to-face battle. You remember, Giovanni suddenly got an emergency phone call before Ash was to battle him at the Viridian Gym (after Gary had been defeated), so Jessie and James had to battle Ash instead.
In the GameBoy Pokemon series, Giovanni sees the error of his ways after being ultimately defeated by your trainer in R/B/Y, and disbands Team Rocket. But his followers remains, and in G/S/C, TR executives are keeping the Rockets together, waiting for their revered leader to come back and rule over them again. However, Ash seems incapable of disbanding Giovanni's organization in the anime, so Team Rocket continues, at least for now.
Giovanni appears only rarely, so his true identity remains a mystery. Is he really Ash's father? Will he ever truly take over the world? And what's in store for Team Rocket? Only time will tell...