Dont forget, you can always pull the parody card and make something "inspired by" the original, that way the designs don't have to be exact.
One thing I've found helpful recently, if the character you're trying to make has a Wikipedia page with a description of their appearance, copy it into ChatGPT or something like it and ask
Summerise the following passage in 15 short words or phrases, separate each one with a comma
The list it gives you should be a good start to use as prompts!