Hmmm my go-to pets for large, intimidating and generally badass would happen to be the Mortiking and Magnus, I mean just the standard pose Mortiking looks like it would wreck you just for looking at it funny:
But the bloodred and reborn Mortikings are pretty awesome too.
It's probably not quite the level of bad-ass you're looking for, but I feel like the nostalgic Magnus would suit him c:

I like the 0507 but I think he looks a bit more mischievously intimidating than flat out scary, but I have to admit it's art is awesome! But the 1107 is super awesome and pretty basass too. I probably haven't helped much but at least that's something else to think about c:
Yeah Mortikings are one of my favourite pets, I used to have a Bloodred too.
Never really thought to look at Nostalgic colours, since they're usually too cutesy. I'll definitely consider him! But if I do go with the experiments I might just go with the 1107 since he looks more weathered and rugged, rather than the sly 0507.
You did give me something to think about, thanks! : )
