There is a Pokemon that cannot be traded in your party?

Question

I recently obtained omega ruby from my friend and I cannot trade shiny beldum acroos to another game, please help.
Thanks

Answer 1

Metagrossite

I'm guessing this is from Omega Ruby to XY
The event Beldum is recieved holding a Metagrossite.
Mega Metagross does not exist in XY and therfore disallows the player to trade it across

Comments

Oh yeah I forgot about that

Answer 2

This is because it is an event Pokemon, and event Pokemon (as well as some other special Pokemon like Cosplay Pikachu and Black/White Kyurem) can't be traded over the internet.

Source: Experience

Comments

Thanks