Cheapest priced copy (Doctor Who): $0.59 at Card Kingdom, near mint, their price list as of .
Dalek Squadron 
Artifact Creature — Dalek · 3/3 · Uncommon · Doctor Who · #538
Menace
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $0.59 to $19.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Doctor Who | 65 | Uncommon | $0.59 | $9.99 |
| Doctor Who | 538 | Uncommon | $0.79Out of stock | $1.49 |
| Doctor Who | 670 | Uncommon | — | $15.99 |
| Doctor Who | 1129 | Uncommon | — | $19.99 |
8 rulings from Wizards of the Coast
- 13 October 2023If myriad creates more than one token for any given player (due to an effect such as the one Doubling Season creates), you may choose separately for each token whether it's attacking the player or a planeswalker they control.
- 13 October 2023If the defending player is your only opponent, no tokens are put onto the battlefield.
- 13 October 2023Although the tokens enter the battlefield attacking, they were never declared as attackers. Abilities that trigger whenever a creature attacks won't trigger, including the myriad ability of the tokens. If there any costs to have a creature attack, those costs won't apply to the tokens.
- 13 October 2023Any enters-the-battlefield abilities of the copied creature will trigger when the token enters the battlefield. Any "as [this permanent] enters the battlefield" or "[this permanent] enters the battlefield with" abilities of the copied creature will also work.
- 13 October 2023The term "defending player" in the myriad rules (or any other ability of an attacking creature) refers to the player the creature with myriad was attacking at the time it became an attacking creature this combat, or the controller of the planeswalker or the protector of the battle the creature was attacking at the time it became an attacking creature this combat.
- 13 October 2023Each token copies exactly what was printed on the original creature and nothing else. It doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.
- 13 October 2023The token creatures all enter the battlefield at the same time.
- 13 October 2023You choose whether each token is attacking the player or a planeswalker they control as the token is created.