First thing I thought of when I considered doing this, was a modern far more beefcakian sprite, that isnt even garish at all.
Leo From Warzards

Regardless of how ridiculously beefcake it is we dont mind at all, I think because it's more succesful at imitating what a barbarian beefcake game ought to imitate
Frank Frazetta

There's something undoubtably Frazetta that works regardless of color limitation, strong undiffused lightrource on top and good action lines in posing. So I set out to imitate frazetta with Altered Beast limitations.
my hi-Contrast Altered...Barbarian

Nothing here related to pixels, just hi contrast and a tweaked pose, but I think it already makes for good Barbarian Beefcake gameart. The pose tweak was minor, I think it would work without it but I would've been frustrated working with that horrid pose without tweaking it even a little insignificant bit.
This is the way I pixeled it.

I did the best I could pixelwise, but I'm out of shape so it might not be the best.
EDIT: higher contrast sprite

I wanted to make the shading more Frazetta-ish...and I also tried to make his face more AncientGreek/Roman than Amerigan/English...
He ended up looking a bit like a Charlton Heston in a purple dyed Liono getup...right?