Dewgong. Long has it been overlooked, forgotten, and doomed to mediocrity and limited competitive viability. Not that this is undeserved. It has a decent overall base stat total, but with stats that are too rounded without being strong in any one area, it fails to serve any one role very well. Not bulky enough to make good use of Hydration or Ice Body, and way too lacking in any offensive means. It’s based on the animal Dugong, a relative of the manatee, the lovable sea cow.
Not all hope is lost for Dewgong however. It does have the aforementioned Hydration, which is quite simply one of the best defensive abilities. It might not allow the rain sweeping that Swift Swim provides, but being able to immediately be healed of the self-induced Sleep of Rest, it allows for a one-turn full restore. On top of this, it has access to both Ice and Water priority moves: Aqua Jet, and Ice Shard. Most have only access to one or the other, such as Mamoswine and Lapras. But since it lacks a good Attack stat (or Special Attack) it can’t make the best use of these. Lastly it gets a lot of interesting moves that it COULD make good use of, providing it had: higher stats, and somehow access to more than 4 moves at a time. Signal Beam, Drill Run, Stockpile, Fake Out. Classic example of four moveslot syndrome.
Back in the days of Red/Blue/Yellow was probably when it shined most, despite not having access to Hydration. It had a 95 Special stat, meaning it could actually tank pretty well AND hit decently hard, instead of just having a good Special Defense. However, even then it was greatly outclassed by Lapras, which had equal Defense and Special stats, but with much higher HP and only a cost of 10 Speed. Lapras also had access to a far more diverse movepool. Now that Lapras also has Hydration, it seems Dewgong will always be out-shined by the Transport Pokémon.
It’s unfortunate that Dewgong has been delegated to the back row of Ice/Waters, because I’ve always loved the design. Seel is especially adorable, and would definitely make it to the final rounds in a cutest Pokémon contest. Even though it can’t make its mark competitively, it still has enough tools to be an effective teammate in a regular playthrough. It’s a fun alternative to mix things up but you won’t feel like you’re giving yourself too much of a handicap. All of this said, I love Dewgong, both for its design and the nostalgia of fighting against Lorelei in Red/Blue. I don’t think it needs to be improved, because if all Pokémon were on an even tier it’d take away a lot of what makes Pokémon fun and interesting.
