The Entei (10 / 147) card can be found in the Aquapolis set.
Recently sold 1 times and based on those sales is worth around £21.22.
Currently, there are 3 open listings for this card on ebay.
This card sells in the range of £21.22 to £21.22, making it very stable.
This Rare card was illustrated by Atsuko Nishida.