Pokémon TCG · Undone Seal · Japanese · #20

Tentacool #20 (Japanese) price

Name: Tentacool #20 (Japanese, Undone Seal)
Brand: Pokémon
SKU: JP-UNDONE-SEAL-20
Price: 1.75 USD

Undone Seal20

Add to my collection Get the iPhone app

Market prices

$1.75TCGplayer market price · Near Mint

€0.79Cardmarket price trend · Near Mint

–7-day change

#71 of 83Value rank in the set

Price history chartSee it in Sparkl Undone Seal master set · 83 cardsOpen in Sparkl Graded prices · PSA, CGC, BGSIn Sparkl Pro

Tentacool (#20, Common) is a card from the Japanese Pokémon set Undone Seal. Near Mint (1st Edition), it has a market price of about $1.75 on TCGplayer and €0.79 on Cardmarket (updated November 12, 2026). Among the 18 Common cards of Undone Seal, it is the 14th most valuable. Converted to dollars, its Cardmarket price is 50.0% lower than its TCGplayer price.

Tentacool #20 prices by finish

Finish	TCGplayer	Cardmarket
1st Edition	$1.75	€0.79
Unlimited Holo	from $0.90	€0.79

Near Mint prices: TCGplayer market price, lowest TCGplayer listing, Cardmarket price trend, updated November 12, 2026. “From” marks a lowest listing: an asking price, not a market value.

Price charts, graded prices from PSA, CGC, BGS, SGC, TAG and ACE, PSA population counts and recent sold listings are in Sparkl Pro.

Embed this price on your site

Paste this where you want Tentacool #20’s live price box. It updates daily.

<iframe src="https://sparkl.gg/pokemon/japanese/undone-seal/tentacool-20/embed/" width="360" height="148" style="border:0;max-width:100%" loading="lazy" title="Tentacool #20 price"></iframe>
<p style="font:12px/1.4 system-ui,sans-serif;margin:4px 0 0">Prices: <a href="https://sparkl.gg/pokemon/japanese/undone-seal/tentacool-20/">Tentacool on Sparkl</a></p>

About this card

Set: Undone Seal (Japanese)
Number: 20
Rarity: Common
Finishes: 1st Edition, Unlimited Holo
Rank in its rarity: 14th of 18 Common cards
Against its rarity’s median: 0.4× the median ($4.06)
Cardmarket vs TCGplayer: −50.0% after conversion ($1.1081 per euro)
Released: January 16, 2004
Print language: Japanese

How this page is made: Near Mint prices from TCGplayer and Cardmarket, refreshed daily; ranks, medians and comparisons are computed by Sparkl from those prices.

You are viewing the free public price page

See everything about Tentacool in Sparkl

Its price history chart, every finish and graded prices
The Undone Seal master set, card by card, with every price
Scan your cards with your iPhone: set, number and finish are filled in for you

Open in Sparkl Get the free iPhone app

Free on iPhone and the web

Most valuable Undone Seal cards

Groudon ex#56 · Rare Holo · €107.99Open in Sparkl
Regirock ex#55 · Rare Holo · from $600.00Open in Sparkl
Kyogre ex#39 · Rare Holo · $99.99Open in Sparkl
Ninetales ex#18 · Rare Holo · from $399.99Open in Sparkl
Regice ex#38 · Rare Holo · €83.72Open in Sparkl
Registeel ex#72 · Rare Holo · $70.00Open in Sparkl

The 10 most valuable · See all 83 cards in Undone Seal

Next to Tentacool #20 in Undone Seal

Vulpix#16 · Common · $6.00Open in Sparkl
Ninetales#17 · Rare Holo · $39.99Open in Sparkl
Staryu#22 · Common · $12.00Open in Sparkl
Corsola#23 · Uncommon · $5.50Open in Sparkl
Feebas#24 · Uncommon · $0.50Open in Sparkl