What does this star symbol mean in Pokemon X Pokedex

Solution 1:

Based on this video

, that does appear to be a shiny pancham. Congratulations. If you want to be sure, shinies apparently sparkle when you send them into battle as shown in the video

This thread also indicates that the shiny pancham is brown.

Bulbapedia confirms that the star indicates that the Pokemon is shiny.

Solution 2:

Yep, that's a shiny! Congratulations, they're incredibly rare!

Solution 3:

The red star means it's a shiny.

That mark has been carried forward from Black/White/Black 2 and White 2. I can confirm, as for these games I:

  • Pokétransferred a shiny from Diamond and
  • Caught shiny Haxorus, Gibble, Dratini.

Another way to tell, the Pokédex number on the summary turns red, further confirming it's a shiny Pokémon.

Since I haven't seen any shiny so far in my Y game, and the picture the OP has uploaded doesn't show it, I can't tell if the Pokédex number shown on the summary also changes its color (if you're looking at a shiny Pokémon in this generation).