Create an empire title exactly like how they are done for the rest of the emperor titles such as calling it e_the_claw then give it localisation, make the coa for your e_the_claw title the same as the k_claw (or whatever it is called) by copying the same image, in the creation of the title you must move the existing claw and dragonstone title to be underneath it as de jure same way it is done for all other titles-Adding an empire of The Claw, having it being available only in the first two start dates, having the same CoA as kingdom of The Claw, which is already in the game, and making kingdoms of The Claw and Dragonstone de jure parts of it.
In the same way k_the_most_devout has its special title define title = CLAW_KING, title_female = CLAW_QUEEN then give these localisations.-Making said empire/kingdom's ruler having the title Crab King/Crab Queen
Change the culture of every staunton character to be clawman in the history files-Making Staunton dynasty have clawman culture
Give him those traits in the history files-Giving certain traits to Monford Crabb
In those title put capital = x with x being the province id of the whispers, this can be found in map/definition.csv or in history/provinces-Making The Whispers a de jure capital of Duchy of Crackclaw Point, Kingdom of The Claw and Empire of The Claw
Change the crackclaw point's flag in gfx/flags to be the same image as found in the dynasy coa file for house crabb-Changing Duchy of Crackclaw Point's CoA to be same as House Cabb's
In the dynamic_coa events copy how it is done for the others but change the title used for the basis of the title flag to be that of the craclaw point flag which you just changed to House Crabb-Adding house Crabb's CoA as CoA of the Iron Throne if the title is held by member of house Crabb.
Sorry if these answers seem a bit vague but the specifics can all be found here on the modding wiki and I am frankly a bit to lazy to type out a step by step guide for each step