Bitterfrost frontier hero collection specifies the need of 5 items, of which the first 2 does not specify it must come from a champion.
Hence, I spent quite some time killing griffons getting frustrated by the low drop rate, until someone else told me it had to be a champion.
So, I suggest, to save other’s the frustration, that anet adds the tag champion to the description, so people won’t farm regular griffons
