Petra Sphinx [Legends] Mirrodin Besieged In the reflection

In the reflection

{T}: Double the amount of each type of unspent mana you have

Set: Worldwake Type: Legendary Planeswalker — Jace Rarity: Mythic Cost: {2}{U}{U} +2: Look at the top card of target player's library

Then each player reveals their chosen card

−2: Reveal the top four cards of your library

Petra Sphinx [Legends] Mirrodin Besieged In the reflectionSet: Legends Type: Creature Sphinx Rare Cost: {2}{W}{W}{W} {T}: Target player chooses a card name, then reveals the top card of their library. If that card has the chosen name, that player puts it into their hand. If it doesn't, the player puts it into their graveyard. What walks on four legs in the morning, two legs in the afternoon, and three legs in the evening?