Can I build a deck together with friends on TCGSwap?

Yes. Every deck on TCGSwap has a Collaboration Space. You can invite up to 5 friends; they can suggest card changes, discuss ideas, and playtest proposals. You review and apply suggestions before anything changes in your deck.

How does deck collaboration work?

It works like a pull request for your deck. Collaborators open the deck editor, make their proposed changes, and submit a suggestion with a note. You get notified, open the comparison view to see exactly what they changed, and choose to apply all, cherry-pick individual cards, or decline. Nothing changes in your deck until you approve it.

Can collaborators chat and discuss the deck?

Yes. The Collaboration Space has a shared group discussion thread for the whole deck, plus a per-suggestion Q&A thread for each proposal. You can @mention teammates and link specific cards inline.

Is collaborative deck building free?

Yes, collaboration is free for all TCGSwap users during beta. You can invite up to 5 collaborators per deck.

Does TCGSwap work for MTG, Pokémon, Yu-Gi-Oh and One Piece collaboration?

Yes. The Collaboration Space supports all four games — Magic: The Gathering, Pokémon TCG, Yu-Gi-Oh and One Piece. Format validation and card prices are included for each game.

Sea Monster · Eighth Edition 99★/711

Sea Monster (Eighth Edition 99★/711), Common, Creature — Serpent. Market price €0.29, up 1.6% this week, relatively stable over the last 11 weeks. Illustrated by Daniel Gelon. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

First printed in Tempest on 14 October 1997.

More Sea Monster printings

Sea Monster · Tenth Edition — €0.11
Sea Monster · Ninth Edition — €0.09
Sea Monster · Ninth Edition
Sea Monster · Eighth Edition — €0.04
Sea Monster · Seventh Edition — €0.11
Sea Monster · Seventh Edition — €3.36
Sea Monster · Classic Sixth Edition — €0.18
Sea Monster · Tempest — €0.07

Weekly price history

Over the last 11 weeks it has sold for between €0.28 and €0.29. That is up 4.8% from €0.28 10 weeks ago. Right now it is at its highest tracked price.

Week	Market price
2026-W31	€0.28
2026-W32	€0.28
2026-W33	€0.28
2026-W34	€0.28
2026-W35	€0.28
2026-W36	€0.28
2026-W37	€0.28
2026-W38	€0.29
2026-W39	€0.29
2026-W40	€0.29
2026-W41	€0.29

Price in context

Sea Monster ranks #434 of the 701 priced cards in Eighth Edition. The median Common in the set is €0.29. The 701 priced cards in Eighth Edition are worth €2579.61 together; this card is less than 0.1% of that. The set’s value is up 2.1% this week. Over the last 11 weeks the set’s value went from €2399.49 to €2549.97 (+6.3%).

Top chases in Eighth Edition

Birds of Paradise 233★ — €284.72
Grave Pact 137★ — €175.22
City of Brass 322★ — €149.46
Intruder Alarm 86★ — €96.39
Curiosity 72★ — €61.29

Set value over 11 weeks · same 667 cards each week
Week	Set value
2026-W31	€2399.49
2026-W32	€2367.84
2026-W33	€2369.12
2026-W34	€2386.22
2026-W35	€2373.86
2026-W36	€2360.69
2026-W37	€2369.34
2026-W38	€2377.52
2026-W39	€2354.45
2026-W40	€2498.25
2026-W41	€2549.97