Secret Tunnel

The gag hides in the rules text, not the type line: a land that "can't be blocked," a clause that does nothing at all on a permanent that never enters combat. It reads as a wink, a piece of evasion boilerplate stapled to something that will never attack unless another card animates it. The functional half is the activated ability, which spends four generic mana to hand unblockable status to two of your creatures that share a type. That tribal rider is the constraint that pays for the effect: it is a payoff wired for tribal boards, not a blanket "your team gets through" button, and it wants a shared subtype already on the battlefield before it does anything at all. Because the land also taps for a plain colorless, it justifies its slot the way any land does (it makes a land drop and produces mana), then converts a surplus of mana in the late game into a two-creature alpha strike that skips the blocking step entirely. And because the evasion lives on a land rather than on a dedicated creature, it survives the board wipes that would answer a keyword-granting body, sitting quietly in the manabase and threatening to close a game once a tribal board has both the creatures and the mana to punch through.