Hey, I'm about as good with graphics as I am with flying unassisted, but I'm willing to put up. Someone who wants to make a quick $3, turn these pix into cards using SG's templates, then Email me the art with your PayPal address, and I'll pay up.
Card 1:
School of Piranha (Upgrade: School of Jellyfish)
5 Water
4/3 (Upgrade: 6/3)
When School of Piranha leaves play for any reason, it spawns 3 Piranhas (Upgrade: Jellyfish).
Card 2:
Piranha (Upgrade: Jellyfish)
2 Water
1/1 (Upgrade: 2/1)
2 Water: Frenzy - For each Piranha in play, this Piranha gains +1/+0 until the end of the turn.
(Upgrade: 3 Water: Sting - For each Jellyfish in play, this Jellyfish deals 1 damage to target creature or player.)
Special: Jellyfish/Piranha is not purchasable in the Bazaar, they ONLY come from killing Schools.
Images below.