I’ve always thought Toucannon was a really neat Pokémon, but it’s never seemed to live up to its inspiration in terms of how it battles. Beak Blast is a cool idea but it’s super one-note to have Toucannon‘s gimmick rely on a single pretty mediocre physical move.
In order to more closely align with the cannon that the bird gets its name from, I thought the crest should increase Toucannon’s fairly weak special attack by 50%. It would also gain the ability Boom Bird, which makes special normal, flying and fire type attacks never miss, but causes recoil.
My second suggestion is a crest for Tapu Bulu that effectively makes any move Bulu uses Play Rough. Justice for Bulu.