Every Tentacool card we price, most valuable first. Prices are what copies actually sold for, updated daily.
What a Tentacool card is worth
The most valuable Tentacool on this list is Tentacool from Legendary Collection at $145.28£109.34€127.94, and the 14 priced copies across 13 sets are worth $258£194€227 together. Most of that sits in a handful of printings: the older the set and the scarcer the print run, the wider the gap to the rest.
Tentacool is printed in Japanese as well: 12 cards across 10 sets, the most valuable of them Tentacool (Master Ball Pattern) from Pokemon Card 151 at $12.04£9.06€10.60. Switch the list above to Japanese to read those, or to Both to rank the two catalogues against each other.
The highest PSA 10 on record for Tentacool sold for $501.29£377.29€441.47. 1st Edition and reverse holo printings are priced separately from the standard card, because they do not trade at the same money.
If you are trying to identify which Tentacool you have, the set name is printed on the card and the collector number sits in the bottom corner. Open the card here and the page carries every printing of it, the graded prices, and whether grading the copy is worth the fee. Sets to start with: Legendary Collection, Aquapolis, EX Legend Maker.