The Dewgong (40 / 110) card can be found in the Legendary Collection set.
Recently sold 4 times and based on those sales is worth around £24.84.
Currently, there are 2 open listings for this card on ebay.
This card sells in the range of £15.67 to £34.01, making it quite stable.
This Uncommon card was illustrated by Mitsuhiro Arita.