The Octillery (H20) card can be found in the Aquapolis set.
Recently sold 9 times and based on those sales is worth around £31.82.
Currently, there are 6 open listings for this card on ebay.
This card sells in the range of £13.21 to £50.43, making it quite volatile.
This Rare Holo card was illustrated by Kouki Saitou.