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Byrdonis Egg — Quest Quest Card in Slay the Spire 2

Updated 17 Oct 2026 Source Slay the Spire 2 card data (spire-codex.com API), 577 cards retrieved 17 October 2026 By
Data status: The facts on this page were checked against the source named above. Game values can still shift with a patch, so re-check anything that looks off.
Byrdonis Egg card art
Byrdonis Egg

Can be hatched at a Rest Site.

CharacterQuest
TypeQuest
RarityQuest
Cost-1 Energy
TargetNone
KeywordsUnplayable

Card text

Can be hatched at a Rest Site.

This card has no upgraded text in the card data, so it does not change on upgrade or the change is not text.

Other Quest cards at -1 Energy

  • Lantern Key — Unlocks a special event in the next Act.
  • Spoils Map — Marks a site of 600 extra Gold in the next Act.

Other cards with Unplayable

  • Ascender's Bane —
  • Bad Luck — At the end of your turn, if this is in your Hand, lose 13 HP.
  • Burn — At the end of your turn, if this is in your Hand, take 2 damage.
  • Clumsy —
  • Curse of the Bell —
  • Dazed —
  • Debt — At the end of your turn, if this is in your Hand, lose 10 Gold.
  • Decay — At the end of your turn, if this is in your Hand, take 2 damage.

Where to go next

All 577 cards — the full table, filterable by character. Efficiency tier list — every measurable card ranked.

Rarity system explains how often this card appears. Enchantments covers the modifiers that can change it.

Frequently asked questions

What does Byrdonis Egg do in Slay the Spire 2?

Can be hatched at a Rest Site.

How much does Byrdonis Egg cost?

-1 Energy. It is a Quest Quest card.

More Slay the Spire 2 guides

Sources

Figures and item data on this site are read from the game’s own reference wiki before publishing. Where a value could not be confirmed there, the page says so instead of filling the gap.