give it to seadra it will become kingdra but i suppose you have to trade it first to another game and than back (but I'm not sure about the trading part)
The following Pokémon are obtainable in Pokémon Crystal Version: 1st generation Dragon Pokémon: Dratini, Dragonair and Dragonite. --Dratini is given to you by the Dragon Masters in the Blackthorn City Dragon Den in the shrine after defeating Claire, the Blackthorn City Gym Leader, the last one (this is in Heartgold and Soulsilver but can be done wrong and result in you not having a Dratini with Extremespeed).Note: this will require a pokemon who knows the HM Whirlpool (HM08). Dratini and Dragonair can be fished for with the Super Rod on Route 46 with Magikarp, Dratini, and Dragonair the common, mid-common, and mid-rare pokemon respectively found this way. 2nd generation Dragon Pokémon: Kingdra. -- You must trade a Seadra with a Dragon Scale attached to it with a Gold, Silver, or Crystal version. A Dragon Scale is found in each second generation version in the Southeast corner of the Dragon Den just east of the shrine.
Causes Seadra to evolve into Kingdra when traded
You will find the dragon scale deep in Mt. Mortar, which is between route 42 and Ecruteak City.
Trade the red scale to mr pokemon
find a bagon with a dragon scale attached to it look in meteor falls and go to the waterfall and keep looking for dragon claw when you find it in the tiny space.you'll find a bagon.
In Pokémon Crystal (GBC), there is no Heart Scale item. The Heart Scale item was introduced to the Pokémon video games in Generation III (3) (Ruby/Sapphire/Emerald). Thus, you cannot get the Heart Scale in Crystal. There is no Generation II-III trading, so there is no possible way to use the Heart Scale in Pokémon Crystal Version, sorry!
You can catch a Seadra in the wild at Dragon's Den or evolve a Horsea into Seadra via leveling up while holding a Dragon Scale. Finally, you can evolve Seadra into Kingdra by trading it while holding a Dragon Scale.
In "Liquid Crystal," you can obtain a dragon scale by defeating a dragon enemy, typically found in specific locations within the game. Once you defeat the dragon, it may drop a dragon scale as loot. Additionally, some quests or crafting recipes might allow you to acquire scales through other means, such as trading or completing challenges. Make sure to explore thoroughly and engage with various game mechanics to increase your chances of obtaining one.
you need to give seadra a dragon scale (which you can obtain by catching or using thief on some dragon Pokemon (bagon for instance) and theres a chance that they will be holding a dragon scale) and then you trade your seadra holding the dragon scale and voila you have a kingdra
Because it has to be on Pokemon Diamond,pearl or Plainum.
go to a cheese store. they have many scales there. it is in pallet town
get a dragon scale and trade it then trade it back it will evolve