The chance may be low, but I was VERY lucky indeed...I received the Storm Hound pet on my second chance at "Throwing in crowns" in Malistaire's second chance chest...I was going for his Athame item. Good luck to you, though, for storm wizards I think the Storm Cat would work well (4 pip 450 damage? and +25% next storm damage trap). Break a shield then add a trap...just saying
The only way to get one through hatching is to find someone who has one and that they are willing to hatch with your pet and get a more rare pet than the storm hound and pay more.Or else you can always buy it for crowns or keep on fighting.