Simple suggestion, so there's not really much to say about it. How about a mutation where the fur on lions' tail tips is bigger and fluffier? I'm not saying make the whole tail fluffy, but just make the fluffy tip bigger.

This mutation would be similar to most of the main muts currently, I think. Since it would just be based on the main colour, it wouldn't need the vast amounts of art that many mutations do, which could increase the speed of rolling it out.

Only limitation would be that the mutation wouldn't be possible on Incubus, Crested, Tsavo, and Pariah manes as those already have slightly different tails.