Well... in Y there are dragalge, noivern, garchomp, and flygon.
For stats:Dragalge :
HP:65
Attack: 75
Defense: 90
Sp. Atk: 97
Sp. Def: 123
Speed: 44
Noivern:
HP: 85
Attack:70
Defense:80
Sp. Atk:97
Sp. Def:80
Speed:123
Garchomp:
HP:108
Attack:130
Defense:95
Sp. Atk:80
Sp. Def:85
Speed:102
Flygon:
HP:80
Attack:100
Defense:80
Sp. Atk:80
Sp. Def:80
Speed:100
Overall, I would recommend noivern because it has a wide move pool and an amazing speed. The only problem is that you get noivern at the end of the game. But luckily you have a friend that can trade you one early in the game. Hope this helps!