Rushwood Dryad

Forestwalk is the oldest of Magic's evasion keywords, a holdover from the days when designers assumed every opponent would be running the same forests you were. Against an opponent who controls a Forest this body simply cannot be blocked: clean, repeatable damage that asks nothing of you but a willing target. The price is the one every landwalk creature pays: the evasion hinges on the defender's mana base, not yours, so the creature that walks through one matchup is a vanilla beater in the next. That conditionality is the entire design. The keyword is also paid for in toughness. A green two-drop with no abilities was historically built on the Grizzly Bears chassis, and shaving a point off that to land at 2/1 is the cost of evasion that only cashes out some of the time, against an opponent whose colors you do not control. Later evasion (flying, menace, the unconditional unblockable text on creatures like Invisible Stalker) abandoned this model precisely because contingent-on-the-opponent keywords are feast or famine: dead weight when the mirror never comes, a clock with no answer when the colors line up. What complicates the easy "it died out" story is that typed nonbasics keep the keyword honest: original duals and shocklands carry the Forest type, so a multicolor opponent often still controls a Forest for this to walk past. Forestwalk did not fade because the math turned against it. It faded because designers stopped wanting evasion you could not rely on.