Anamorph

tiny creatures are an automatic succeed Small creatures roll 1 d20 if lands on one spell fails and you can retry right after. medium creatures roll 1 d4 if odd spell fails and you cannot use it again until a short rest. large creatures roll 2 d20 both must land above 9, if they do not spell fails and cannot use for 2 short rests. large creatures roll d100 must land over 90, if fail then 1 long rest. any if spell succeeds no need for any rest

Certain animals obtain special abilities.