Giant Crab

Pay one blue mana and the crab becomes untouchable: that is the entire pitch, and it is a study in how unevenly the mid-90s priced defensive bodies. The intent is legible. A creature that can dodge removal at the cost of a single mana, large enough to wall off a flank. The friction is that shroud cuts both ways, locking out your own combat tricks and Auras for the turn you turn it on, and the only other text on the body is that self-protection clause, so there is nothing worth shielding once the crab survives. The activation is also a tax you pay reactively, after an opponent has already committed a card to killing it; the rest of the time the ability sits idle. Self-protection on a creature wants a payload worth guarding (an engine, an evasive clock, an oversized body), and a 3/3 whose only trick is the shield itself is none of those. The design lesson outlasts the card: shroud as a built-in ability is only as valuable as the thing it protects, which is why later self-protecting creatures paired the keyword with evasion, a death trigger, or a much harder-to-kill body. Here, the keyword guards a wall, and the wall is the only thing it has to offer.