this was an interesting challenge

this was an interesting challenge,

it's tough to do some of these where I have leveled so many pets past lv 2, I don't have the full complement of pets to choose from.

went with Voodoo Figurine vs the mech, (this is the hardest part of the matchup imho, having an undead with an elemental attack is key) Voodoo killed the mech and had 1 death round to apply immolate to the bird.
po wow
then used toxic wasteling (uncommon quality) vs the bird. was able to kill the bird, and survive to face the rat.

round 1 the rat used survival, this allowed the application of corrosion, then the rat killed the Wasteling.

finally sent in an uncommon Speedy, used shell, then spammed bite, the rat made the curious decision to use survival when it's cooldown was up, that extra round of damage allowed Speedy to carry the team to victory.

I'm not sure how decisive "Shell" was, I could have run a mr pinchy or strand crawler there as well.