From Bulbapedia, the community-driven Pokémon encyclopedia.
This is a list of Pokémon obtainable from events found in the Generation VI Pokémon games. These specific instances of Pokémon can only be obtained once per game; however, some may also be obtained in other ways as well. In addition, some Pokémon, such as Rotom, and Banette have a chance of being found in trash cans around the Kalos region on a weekly basis.
Once the player has reached Aquacorde Town and has chosen a nickname, Tierno presents the player with the choice of three starter Pokémon the player can choose from.
After meeting with Professor Sycamore in Lumiose City and defeating him in battle, he will give the player a choice of one of the Kanto starters to take with them on their journey. If the player's party is full, he or she will be prompted to send one of their party members to the PC to make room for the new Pokémon. The player will receive a Mega Stone corresponding to that starter's final evolution after choosing their starter.
Players of X who pick Charmander will receive Charizardite X, while Y players will receive Charizardite Y.
This Snorlax is blocking the bridge on Route 7. After successfully borrowing the Poké Flute from the owner of Parfum Palace, the owner of Shabboneau Castle will play the flute, prompting the Snorlax to wake up and attack.
After defeating Korrina at her gym, she will immediately invite the player to a rematch atop the Tower of Mastery. There, Korrina gives the player the Mega Ring. After the player has obtained the Mega Ring, the Lucario that showed affection to the player throughout the game will temporarily join their team and fight against the Successor's other Lucario. Both Lucario hold Lucarionite. After defeating or losing to Korrina, the player will have the option to officially add Lucario as one of their Pokémon.
Upon reaching Route 12, the player may speak to a trainer near the gate and he will tell you a story about a Lapras that once saved his life. He will then offer it to the player, believing he or she will care for it better than he can. This Lapras appears on the overworld while Surfing.
On Tuesdays, wild Rotom have a chance of being found in three of the five trash cans inside the Lost Hotel. On rare occasions, this Rotom will appear in one of its five alternate forms.
On Thursdays, wild Banette have a chance of being found in three of the five trash cans inside the Pokémon Village.
Xerneas and Yveltal
In the player's final confrontation with Team Flare at their secret headquarters in Geosenge Town, XerneasX or YveltalY will be awakened and attack the player. Similar to Reshiram and Zekrom in Black and White, the player must capture it to proceed to the final confrontation with Lysandre; If it is defeated, it will instantly respawn. If the player's party is full, the player will have the chance to send one of his or her Pokémon to the PC to make room for the Legendary Pokémon.
After defeating the the Kalos Elite Four, the player may explore the deepest parts of Terminus Cave. At the end of the cave, the player will encounter Zygarde.
After defeating the Kalos Elite Four, a man in the Pokémon Village blocking access to the Unknown Dungeon will disappear. Mewtwo rests inside, and will attack the player when interacted with. After capturing Mewtwo, players of X will receive Mewtwonite X, while Y players will receive Mewtwonite Y.
After defeating the Kalos Elite Four, one of the legendary birds of Kanto will begin roaming around Kalos. The bird that appears depends on the starter the player chose. Unlike previous roaming Pokémon, however, the bird will flee immediately after the player sends out a Pokémon, without giving the player a chance to issue a command. After encountering the bird ten times, the bird will flee to the Sea Spirit's Den, where the player can challenge it normally.
If the player chose Chespin:
If the player chose Fennekin:
If the player chose Froakie: