Things that are taken out of the crown store are generally destined for gambling crates. I'm pretty sure the original baby netch and a couple of recolors have been in previous crown crate seasons. Unfortunately it's relatively unlikely that they'll make it back to the store for outright purchase.
There were pink ones that I know were in one of the earliest seasons, and I want to say a green one too. I don't know how soon they'll cycle things like that back in. You can always pray to the RNG gods and the ZOS marketing machine.
Unfortunately all three variants of the baby netch have been relegated to crown crates, the pink was in storm atro crates, the moss green was in dwarven, and regular blue was in the wild hunt crates.
The wild hunt crates are coming back for a bit in a few days, so if you want a chance at the netch, you'll have to gamble for it