Silburlind Snapper

A 6/6 for six is generous by mono-blue's usual standards, and that size is the bait: the toll for swinging is the whole design. The Turtle can't attack unless you've already cast a noncreature spell that turn, which is a leash on tempo, not on stats. Blocking is never restricted, so it's a wall on any turn; the only deckbuilding question is whether your spell density is high enough to make it a clock too. This is the recurring blue pattern of gating a fat threat behind the noncreature count a deck was already committed to, rewarding cheap interaction and card selection over a curve of creatures. A cantrip, a removal spell, a noncreature artifact or enchantment fired off on the way to combat pays the toll, though an artifact creature or enchantment creature will not, since those are creature spells. A creature-heavy deck finds a 6/6 statue stranded behind an open red zone. The constraint pays for power that would otherwise read as undercosted, and because the clause never touches the defensive half, the Snapper earns its keep on the back foot regardless of what you've cast. The body stays grounded, too: no flying, no reach, so it holds the ground and leaves the air to someone else. What the noncreature clause buys is a beater that doubles as a stone wall, contingent entirely on a deck built to keep its spell count honest.