Slinking Serpent

Forestwalk on a blue-black creature is the kind of evasion that only works when the table cooperates, and Invasion was built precisely to make that cooperation likely. This was a multicolor set obsessed with gold cards and many-colored manabases, where a green splash was the rule rather than the exception, so a Serpent that slips past anyone tapping Forests had real teeth in the environment it was printed for. The design logic is conditional evasion priced as a discount: a 2/3 for four mana is a soft body, but the green-tax it imposes on opponents pays for the modest rate when the assumption holds. The problem, of course, is that landwalk is the most metagame-dependent keyword in the game; against a deck with no Forest, this is just an undersized Serpent with no relevant text, and Forestwalk has never been a keyword you could rely on outside the set that seeded it. It belongs to a long tradition of color-hosing landwalkers (Forestwalk in particular has bounced between black and blue as an anti-green tool for most of the game's history), creatures whose entire value proposition is a bet on what lands the other side is running.