The Grateful Dead

Stand (Must be attached to another creature, designated as it's user. Can attack Instead of
the user, but both get full combat damage.
if either one of them die, sacrifice the other.)
The Grateful Dead enters the battlefield with
a counter set to "0". On your upkeep, add "1"
to it. every creature (except The Grateful Dead
and it's user) gains a -{x}/-{x} counter on itself
where {x} is the number on the counter.