Iris appears in both the Pokemon Black and White game franchises although she is only the gym leader in White as the youngest gym leader being a 10 year old in the fifth gen. While her mentor Drayden is the eighth gym leader in Black. The player first meets her in Castelia City wherein she helps Bianca as a "bodyguard" while the player goes off to return her stolen Munna.
The player will meet Iris once again when they reach Opelucid City. There they will talk with Drayden and Iris about the various plots and deeds of Team Plasma and its leader Ghetsis and where the trainer fits into this all. In Pokemon White, the trainer can then head to Opelucid City Gym wherein they may face Iris for the Legend Badge. Upon defeating her, the player receives TM 82 (Dragon Tail). Later Iris joins with the other 7 gym leaders to fend off the Seven Sages in N's Castle on the way to the final battle. After going through the Elite 4 and gaining access to Undella Town, players can find her in Cynthia's resort in the summer.
In Pokemon Black, Drayden replaces Iris as gym leader. She will teach the player's Pokemon Draco Meteor, a powerful Dragon-type mood, but only if they have full happiness on an appropriate Pokemon.
Fraxure (Dragon) (Female) Level 41: Dragon Dance, Dragon Rage, Assurance, Dragon Tail
Druddigon (Dragon) (Female) Level 41: Revenge, Chip Away, Night Slash, Dragon Tail
Haxorus (Dragon) (Female) Level 43: Dragon Dance, Assurance, Slash, Dragon Tail
Iris and Clair are the only two female dragon type who are both also the final gym leaders
Iris has an all female Pokemon team
In the anime she plays a similar role to what Misty played in the original series
In Pokemon Black she'll be running the Gym when Drayden retires
Iris resembles Zekrom with her hair though it's unknown if this was done on purpose