Most fierce pet?

[Azunara]

Moths.

Seriously, if it's pointy, flamey, fangy, or clawy, it's probably a good candidate.

[Makoes]

Corehounds scream anger and rage (except Kurken, he's the friendly puppy )
Especially the red ones, seething, burning with rage. Chromaggus for his armored spikey look, and eyes that see into your soul.

Hyena's posatively laugh with delight as they crunch the bones of thier prey. Savagely ripping them appart, all the while sadistically grinning. (Hugs Nanaki fondly)

Felboars demonic appearence scream rage, especially the red ones.

That new greyskinned Windserpent, looks closely andf it does look really terrifiying. Souless eyes rimmed in red, spikey spines and sharp fangs.

Top of the angryist pet list though is deffinitly the red corehound.

[Lotusii]

I doubt a lot of people would agree with my but I think the outland model wind serpents look quite fearsome, but I'm biased because they're my favourite non-exotic pet. But for the MOST fearsome I'd have to go with ravagers. They're covered in spikes and have those nasty fangs. And like someone else mentioned, they seem to quiver with unbridled RAGE.

[Tulune]

Ravagers and the old Croc models. Every so often on the old crocs, their eyes narrow.

[SgtMakkie]

Hahaha Damn you Sat, I was just scrolling through this to see if anyone else had written that and what do I find

What Sat said... Sporebats! ^^