Everyone who has replied that Dewgong is better because of the basic is right.But I am talkin about Dewgong and Gyarados not Maikarp and Seel and here are the reasons why Gyarados is better than Dewgong 1.Gyarados is a hologram (I know it has nothing to do about the card being better fighting wise but it makes the card look a lot cooler than Dewgong and everyone should admit that). 2.Their first attack is the same exact thing except Gyarados has 3 water energy cards needed and Dewgong needs 2 and 1 Colorless.Dewgong might sound better but the next attack has the same energy amount and Gyarados needs 4 Water and Dewgong needs 2 Water and 2 Colorless but Gyarados' takes off 10 more.I know that if you have a Double Colorless in you deck then it only requires 3 for Dewgong but with the maximum amount of 4 in your deck, the chances of getting one out with a Dewgong isn't too good but even if you do have one with it that brings me to reason 3.Gyarados has 20 more HP and can withstand more damage and thats about it but actually I do think that Dewgong is better in a Multi-Color deck but in a straight water deck Gyarados definitely better.Oh and I almost forgot 4.Gyarados has a -30 resistance to fighting (which is probably the most common type at the time) and Dewgong doesn't have any resistance.So, overall I do think that Gyarados is better. Just ''Another'' Helpful hint from, Tom