Root Spider

A defensive body that turns combat math on its head the moment it stands in front of an attacker: the +1/+0 and first strike only trigger on a block, which means the printed 2/2 stat line undersells what it actually does on the back foot. As a 3/2 first striker it cleanly eats most early aggressors without trading, killing a 3/3 before that creature deals damage and surviving anything that deals two or less to it. The catch is the same restriction that balances the rate: nothing happens on offense. Attack with it and it is a plain 2/2, so the card asks to be a wall that walks rather than a threat. It belongs to an early strain of green creature built around the asymmetry between attacking and blocking, a design space later cards explored with dedicated keywords; here the idea is spelled out longhand as a conditional bonus tied specifically to the block declaration. The bonus comes from a triggered ability, so it uses the stack: the attacker gets priority after blocks are declared and before the Spider grows, leaving a window to respond with instant-speed removal and trade up before the first strike ever matters. A modest card from a modest set, but the kernel of its idea (a creature whose body changes shape depending on which side of combat it sits on) is one Magic kept coming back to.