­Squadron Hawk and Infectious Bloodlust say this is okay at common.

I view this ability as a white-centric ability even though it shows up and is encouraged in all colors.

Ummm, Squadron Hawk was introduces as a common and was found to be problematic in general so that doesn't really count IMO since it was it's first time. I'm not sure about it's limited success though. It being reprinted at common in eternal masters definitely doesn't count either.

­Infectious Bloodlust is a mediocre Aura card (and Auras generally suck - everyone knows this, right?) that replaces itself (it's no Rancor though that's for sure) so I hardly see it as proper to use it as a justification for printing a common bear that replaces itself.

This is basically "Regenerate for free, but only 3 times". Feels like a bit much for no added casting cost; with a fiddly implementation.

Needs to be common to work in limited, though.

Hm, I'd argue that Squadron Hawk's brokenness stemmed from carrying equipment (read: Sword of Body and Mind) as a flyer and the fact that it was much stronger in constructed than it was in limited, since you were guaranteed 3 copies of it. This is probably closer to Welkin Hawk than Squadron Hawk, and I don't believe that was broken at all in limited. In constructed, a 2/2 on the ground is way more reasonable to deal with than a 1/1 in the air.

In a large set draft, you can reasonably guarantee 2.4 copies of each common - so you're only reasonably regenerating for "free" (have to pay to recast it, making the regeneration comparison similar to Mire Boa or an unearth card like Dregscape Zombie) once or twice at most. I don't really want to make this a 2/1 or bump it up to 3 mana for that reason, so this is something that I'd want to test out at this power level first.