Taniwha is a rare Legendary Creature — Serpent card from Mirage (MIR), collector number 95. Current market price: $5.58, TCGplayer market prices via Scryfall.
Trample Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.) At the beginning of your upkeep, all lands you control phase out. (They phase in before you untap during your next untap step.)