Originally posted by leonidas he consumed celestials in a non-canon setting.
I may have to disagree here good friend.
The "Black Celestial" arc took place in Fantastic Four #337-341,
and it was the 616 Universe (amongst all creation)
that was in danger due to Galactus' insatiable hunger.
It also involved 616 characters like the FF, Thor, & the Shiar, amongst others.
And it was 616 Galactus in a future a mere 15 years away,
from the date set withIN the 616 Universe at the time.
Now, I'll be the first to make it known,
that all stories that take place in the Future,
are set in alternate realities, that's a fact,
but, unlike mirror realities or diverged Futures,
when one actually travels to a potential 616 Future,
like the FF/Thor & Co. did during said arc,
that potential Future involves the actual 616 characters
represented by their Future-selves.
So in essence, it was 616 Galactus in the "Black Celestial" arc,
well, his 616 Future self anyway,
and the arc, is canon, and there's no doubt about that.