Worked great. I was using Mr. Wiggles lvl 16 to as lvl pet.
Used uncanny luck before swapping back out.
Icefang went down on 2nd run of flock.
Got 1056 xp with lesser pet treat. 2 lvls. not bad.
Thanks for the strat :-)
With 2-1-2 Enchanted Broom you can pretty much kill the Icefang without needing a lvl 25 Backup pet, bring a lvl 1 if you need (the fight doesn't give much XP, around ~700 , but its enough to bring the pets off lvl 1 haha )
Start by negating the Icefang's Blistering Cold+Frostbite damage with the sandstorm, and Wind Up until you kill it, keeping sandstorm active.
Try clearing the 'mostly-beast' backline pets with Batter+Wind Up, and use the lvl 25 backup pet if necessary.
In my case I used a 1-2-1 Mechanical Axebeak, both pets are cageable and can be bought off AH, or made with engineering.
Enchanted Broom is a S/S pet and can pretty much outspeed all pets (unless one of backline has a speed boost of sorts, but nothing it can't handle).