Mothra Larvae

{t} Tap target creature and give it a web token
enchantment that reads: This creature does not
untap normally. Spend {4} to untap it during your upkeep phase. This effect does not stack.
{4}{t} Cocoon: Mothra Larvae remains tapped
and gains shroud until it transforms.
{4} Transform: Sacrifice Cocoon to transform
into Mothra.