All new world Vipers are viviparous or ovoviviparous apart from Lachesis, the Bushmasters.
MH
Who the hell is Pat?
"Pattimuss doesn't run, he prances most delicately, like a beautiful but sad fairy, winged and capped, curly toed shoes on each foot, dancing on dewdrops while lazy crickets play soft music for him to keep time by...." - Wes