Cathar's Companion

A 3/1 body is the kind of stat line that asks to be killed: one toughness dies to nearly every removal spell and trades down against the cheap one-drops and tokens that gum up the ground. The conditional indestructibility is built to invert that fragility, but only on your terms. Cast a noncreature spell and the Dog shrugs off destruction and damage until end of turn, which means it survives the burn spell, the board wipe, the lethal block, so long as you have an instant or a cantrip to pair with the threat. The wrinkle is where the protection lives: the trigger fires on cast, and the indestructibility runs through the current turn only. A noncreature spell on your own turn does nothing for the creature during the opponent's removal step. To keep it alive through a sweeper or a combat trick on their end, you hold up an instant and fire it on their turn, where the protection then lasts until their turn ends, exactly the window you need. That makes this less a beater than a payoff for a deck already leaning on cheap interaction, where the indestructibility rides along on plays you wanted to make anyway. The fragility is the price tag: the body is cheap precisely because the protection is contingent, and a deck that cannot reliably supply noncreature spells is just running an overcosted creature that dies to a stiff breeze.