Greater Basilisk

Deathtouch on a 3/5 body is a deliberate combat lock: anything that swings into it dies, and anything it blocks dies, regardless of size. The five toughness is the part doing the quiet work. A defensive deathtouch creature lives or dies by its toughness, because attackers will simply trade their smallest expendable thing to kill it; five points of toughness is enough that most aggressive boards cannot profitably push through, while the deathtouch makes blocking it a losing proposition for anything larger. That asymmetry (cheap to defend with, expensive to attack into or block) is the whole reason a creature with this stat distribution earns a slot at all. It is also a textbook teaching tool for how deathtouch rewrites combat math, which is why this archetype of fat-toughness deathtouch wall recurs at green common and uncommon across eras: the five-mana cost keeps it from dominating, and the lack of evasion means it is a gatekeeper, not a clock. On its own it ends games slowly, but as a piece that turns the ground into a no-fly zone, the body and the keyword are pulling in the same direction rather than fighting each other.