I think I know the answer but wasn't sure.
If I have a {Sheoldred, Whispering One} in play and one in my graveyard, at the beginning of my upkeep, I reanimate the graveyard one with the one in plays ability. Since it is technically still the beginning of my upkeep, would the Sheoldred I just reanimated ability activate and then I could reanimate another creature in my grave?
I think this is a no but just curious.
MAJOR EDIT: just realized legendary rule. Nvm. DAMNIT. THAT WOULDA BEEN SWEET!
{Mirror Gallery}! No, even though it is still your upkeep, it isn't the beginning anymore, as all abilities have already been put on the stack and are resolving. I'm not 100% on this, but it makes sense to me. Confirmation anyone?
RESOLVED
Gotcha. I thought that's how it worked. Just wanted to confirm. Damn that would be so abused in reanimator if that was the case.
" oh I'm gunna play {buried alive}, search for three Sheoldred, {exhume}, next upkeep, one turns into 4 creatures!!!"