Something odd........
 

looks like what is commonly referred to as a 'terminal spike'. However, this is a seedling zygo that is not even a year old. A single bloom too..........can't wait for the bloom, as its my own zygo cross, and whether or not this is an infamous terminal spike.
http://images.tapatalk-cdn.com/15/06...5651f22faa.jpg

It does look a bit like a terminal spike. But at least Zygos grow new growths regularly, not like a Phal that is typically monopodial. I can't wait to see the bloom too!

That's strange, hopefully it isn't 'terminal' in that way. But that's also extremely exciting you have a first bloom, I'm anxious to see it. :D And it's not even a year old? Wow.

My Wilsonara did this, grew a terminal spike that I didn't recognize it to be terminal until oh just a few months ago - months after the spike had died - and that had me concerned. Then the older pbulb this pbulb grew off started to grow a new growth so that made me think even more that maybe something was wrong with this younger one, but about a month I think after the one growth the pbulb with the terminal spike started a new growth. Long story short I don't know what to make of this but have experienced it myself. Good luck either way, I look forward to keeping up with how it turns out.

Interested at all in sharing what the cross is yet or do you prefer to wait? ;)

Every so often Orchids do what they are not supposed to do. Some years ago I potted up a couple of Zygo back-bulbs with good roots. They promptly started a new growth, from the top of one of the bulbs!

I had an Oncidium Twinkle do that...a new growth from the top.
Plants like to do the unexpected. Keeps the hobby fun.