Tony's team! Aaand some backstory time!
His first Pokemon was Ninetales, who was actually Howard's, but due to Howard's neglect in his later years, Tony bonded much closer with it as a child. Like Tony, his Ninetales revels in the spotlight and is often seen by his side at parties or PR events.
Tony got both Metagross and Porygon Z (in their first evolution) during his time at MIT. Beldum was befriended, but Tony actually helped (or was the driving force) in the creation of Porygon as he wrote the code for it.
Tony got Lucario when it was still a Riolu in the caves of Afghanistan. It was actually Yinsen's, but he asked Tony to take care of it before he died.
Rotom was obtained when it snuck into Stark Tower and started possessing various appliances in the building. Tony managed to lure it out with promises of building custom robots just for it to possess.
*3* And that's it for now! Next up is Loki.