I just wanted to say that I really like the fact that although the upgraded version is "better", the upgraded and standard version would complement each other very nicely in a deck.
Often it's preferred to just have the upgraded card as opposed to the standard version in one's deck, and if not, it's simply because they have different costs/mechanics that if replaced for its upgrade, would mess up the strategy. This card invites both cards to be used together in a deck in interesting ways. I'm sure the trick there is to balance the ratio of Frost Hatchlings to Jays.
Don't quite understand why you just threw ice skills and Blue Jays together but, then again I was thinking some time ago of making a Frost Snail.
The Jays have some interesting mechanics and the submission is overall, a nice, and creative idea which complements one of
Water's central themes.
To improve you could perhaps find a more representative creature for the abilities, or more representative skills for the being. And for whatever creature you choose, less life-like is ironically the way to go.