I thought I was going to have an issue with this. None of my lashers (any type) were over lvl 1. And more, I had nothing with "strong vs beasts" attacks, so I improvised. Slot 1 I used an Amalgam of Destruction (1/1/1), the above Tiny Snowman in 2 and a Corrupted Blood (2/2/x) in 3. I opened with Fire Shield, then Flame Jet and used Immolate until dead -- Lazy and the AoD died the same turn (to FS). Snowman, same thing -- magic hat and both he and Spokes died the same turn. The Corrupted blood used Heat Up and Ooze touch for an easy first try win. Hope this helps someone else like me!
Had to really change it up a bit since i hadn't leveled any lashers to 25 (shame on me). I just did a search on what elemental pets could do stronger damage to beast, and I had Pebble - gotten from Cataclysm quest-related achievements. And for the last slot I was going to go for the DP Hatchling as I saw in the comments above, but then I saw I had my Ravenous Prideling that I recently got to 25 - so I decided to test it out:
Start with Pebble.
Use Quake (lasts 3 rounds)
Rupture (has a chance to stun, it didn't on my attempt)
Use Stone Shot until either pet is dead. Bring in Tiny Snowman.
From here I used Magic Hat to finish off Lazy, The Magic Hat on Spokes.
My Tiny Snowman died before Spokes did, so I brought in the Ravenous Prideling.
Blast of Hatred finished off Spokes.
Skeeto comes in
Blast of Hatred.
When Skeeto is at 825 or less health, use Surge of Power. Boom
I hope my improvisation helps out. :) GL