Wordless Wednesdays: And this is?

Junior J is prolific when it comes to drawings. He churns out a couple of pieces a day, and we've noticed he's now started connecting shapes/colours/details of real objects with his drawings. We no longer get random orange squiggles that are supposed to be a volcanic eruption. He matches colours (spot the banana, he even added the black tips!)... 

He drew everything on his own.
Including the puffer fish (bottom right, partially cut off in this photo).
But I had to hold his hand to do the labelling.

He's able to observe and include details, like the markings on his dinosaur toy.

I drew the outline of the dino with him.
He added the body markings and claws, and the additional background.

He's also started asking us to guess at what he is drawing:

Junior J: Guess what is this, mama?

Me: Erm, a bird?

Junior J: No, its not a bird!

Me: Hmm. A plane?

Junior J: No, not a plane!

Me: Ok I give up, you tell me.

Junior J: No you can't give up!

Me: Erm, a flying reptile?

Junior J: No no no! (getting very frustrated)

Me: I don't know! Please tell me?

Junior J: No I can't! Its a secret!

Ok, so can anyone tell me what on earth this is?

Updated (a day later): So I had loads of guesses over on FB about his drawing, ranging from the Sydney Opera house, to the Batmobile. Lots of us were thinking of airplanes, but it turned out (I managed to squeeze an answer out of him today) it was a sailing ship! Hmmm...

Linking up with (Ok, I cheated, its not wordless this week!):