If there are five or more Heads on the battlefield,
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) two of them and they don't
untapTo untap a permanent, rotate it back to the upright position from a sideways position. Only tapped permanents can be untapped. (CR 701.26) during the Hydra's next
untapTo untap a permanent, rotate it back to the upright position from a sideways position. Only tapped permanents can be untapped. (CR 701.26) step. Otherwise,
revealTo reveal a card, show that card to all players for a brief time. If an effect causes a card to be revealed, it remains revealed for as long as necessary to complete the parts of the effect that card is relevant to. If the cost to cast a spell or activate an ability includes revealing a card, or if a card is revealed because an ability is activated from a hidden zone (see rule 602.2a), the card remains revealed from the time the spell or ability is announced until the time it leaves the stack. If revealing a card causes a triggered ability to trigger, the card remains revealed until that triggered ability leaves the stack. If that ability isn’t put onto the stack the next time a player would receive priority, the card ceases to be revealed.
Revealing a card doesn’t cause it to leave the zone it’s in.
A card that is currently revealed may be revealed again.
If cards in a player’s library are shuffled or otherwise reordered, any revealed cards that are reordered stop being revealed and become new objects.
Some effects instruct a player to look at one or more cards. Looking at a card follows the same rules as revealing a card, except that the card is shown only to the specified player. (CR 701.20) the top card of the Hydra's library and the Hydra casts that card.