Its a fruit! In the top right of the tree.
Can you guess what it really is and how I made it? Hint. Im blue da ba de ba do da bo da ba de.

It looks like the gas sprite from a vespene geyser to me.

Imo it's a scarab sprite, but that's just a guess. In reality, I doubt it's possible to guess.

A gas sprite is green.
A scarab is yellow.
The hint says its blue.

Young Chrysalis placed behind the tree?

During gameplay normal scarabs are blue

Nope.
Second hint: It's a unit.

Broodling?

If not, is it zerg?

It's not a Broodling.
Third hint: You can see part of the unit that sticks out (besides the fruit, duh).

Looks like a Rine's shoulder plate.

High yield mineral chunk

Protoss Probe?

Looks like a high-templar's hip. But since that's not blue it's probably a hallucinated unit that happens to have a golden limb. Which one, I don't know.

It's a zealot.

Ding ding ding!
I actually found this to be interesting. It actually looks like a fruit and can be used for some kind of cheesy plot. IE: The mysterious fruit grows upon the trees of time, and when eaten, grants the user infinite magic.
But yeah, it's a zealot. I found this "blend" by accident.

Zealots are blue..?

Yes player 2 zealots are ;O

Am I the only one who doesn't see the Zealot? Lol.

how could you label a zealot as generally blue? Its more... golden. And I don't even see blue in the picture. Ciara, are you color blind?

I never saw any blue but he stated it was blue so i assumed it was p2 unit