Ah, he's in Survival Breakthrough. 2 to 4 frags per draw I think.

If you cannot wait, use your Arena credits to exchange for his frags. He's kinda pricey thou.

He's also a common rare in Kage treasure, along with his partner Kisame. I've gotten him twice in that treasure now.

And if you got RNG-sus's blessing, you could get him from wheel/ninja pack. That's how I got mine.