The T.A.R.D.I.S

Indestructible, Shroud
When The T.A.R.D.I.S enters the battlefield if
you cast it from your hand, you may search your
hand, library, graveyard and exile for a Doctor
Planeswalker card and cast it without paying its
mana cost.
{7}:Shuffle The T.A.R.D.I.S into your library from
your graveyard or Exile. Activate this ability only if
you control a Doctor Planeswalker and only during
your upkeep
{t}:Regenerate target Doctor Planeswalker