Not sure how many are these are already done, but here are some crests that i would like to see (mainly weaker mons that don't get played otherwise). Keep in mind that many of these may be either very over/undertuned:
-Arbok: give it dark typing and strong jaw
-Avalugg: spdef scales with def
-Basculin: weird one, but give it fell stinger but as an ability (+3 atk if it ko's) [its a piranha or something idk] and 1.5x speed
- Beartic: a combination of snow warning and slush rush, with 1.2x atk
-bellossom: a chlorophyll bellossom holding this also gets drought and
