Hundred-Handed One | Magic: The Gathering
Formats Hundred-Handed One is Legal in
Official Oracle Text for Hundred-Handed One
: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
As long as Hundred-Handed One is monstrous, it has reach and can block an additional ninety-nine creatures each combat.
Official Rulings for Hundred-Handed One
9/15/2013 : Monstrous isn’t an ability that a creature has. It’s just something true about that creature. If the creature stops being a creature or loses its abilities, it will continue to be monstrous.
9/15/2013 : An ability that triggers when a creature becomes monstrous won’t trigger if that creature isn’t on the battlefield when its monstrosity ability resolves.