Just a card with odds 1:3391 
Woah #6 out of 10? Nice!
In fact, it is quite weird but no one bragged about getting a legendary card yet. So I’ll be the first here.
This is by far the rarest for me:
Chase cards have a 1/211 chance for the Masq series. This makes this drop a 1/44,521 chance.
But it gets rarer.
Each of the Masq chases has a card count of 100… Except The Janus Brothers which only has 10.
I can’t confirm this, but this makes getting Janus Brothers even harder (does cc affect chances?).
This can be empirically shown through the number of owners of each chase card (20 owners for each of the normal chases, vs 4 for The Janus Brothers). So assuming that since there are 10x less Janus Brothers cards implies a 10x less chance of getting one puts the odds of this drop at a staggering 1/445,210.
I can’t confirm my hypothesis about card count affecting chase rarity, but I believe the 1/44,521 still stands.
I know it’s late but woah! Congrats on the legendaries 7nik!!
I just opened one free pack of Mythka‘s.“Winter Wonderland“, where I‘m chasing variants and I received two variant cards (one new):
Certainly my luckiest free pack, if not all time, then after the one Butterflies of Polygonia Legendary I got a while back (my second total)! <3
My lucky free pack for today… 
I just opened one of my daily free packs and got my first legendary card.
https://www.neonmob.com/activityfeed/pack-opened/49471500
Yay! 
@7nik ooooohhhh!!! That’s a good one! … and it reminds me that the holidays are right around the corner 
- Joe @ NeonMob
What will you trade with a duplicate legendary?
I have only a single copy of every legendary card. But I’d like to get all Butterfly legendaries.