アストリッド・ペス

アストリッド・ペスが戦場に出るか攻撃するたび、食物・トークン１つを生成する。
まっさらな空 — あなたが手掛かりや食物のうち１つを生け贄に捧げるたび、アストリッド・ペスは探検を行う。

Astrid Peth

Whenever Astrid Peth enters or attacks, create a Food token.
Brand-new Sky — Whenever you sacrifice a Clue or Food, Astrid Peth explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Doctor Who

If no card is revealed, most likely because that player's library is empty, the exploring creature receives a +1/+1 counter.

If a resolving spell or ability instructs a specific creature to explore but that creature has left the battlefield, the creature still explores. If you reveal a nonland card this way, you won't put a +1/+1 counter on anything, but you may put the revealed card into your graveyard. Effects that trigger "whenever a creature you control explores" trigger if appropriate.

Once an ability that causes a creature to explore begins to resolve, no player may take any other actions until it's done. Notably, opponents can't try to remove the exploring creature after you reveal a nonland card but before it receives a counter.

Food is an artifact type. Even though it appears on some creatures, it's never a creature type.

If an effect refers to a Food, it means any Food artifact, not just a Food artifact token. For example, you can sacrifice Tough Cookie (an Artifact Creature — Food Golem) to activate Maraleaf Rider's ability (an ability with "Sacrifice a Food" in its cost).

Whatever you do, don't eat the delicious cards.

You can't sacrifice a Food to pay multiple costs. For example, you can't sacrifice a Food token to activate its own ability and also to activate Maraleaf Rider's ability.

Food

{2}, {T}, Sacrifice this token: You gain 3 life.