Dynamic Wildshape

A character with the Wildshape ability can, as an action*, change shapes multiple times while wild shaped. However, there are some limitations.

1. Subsequent wild shapes must have one lower CR bracket maximum than the last. So if your CR maximum starts at CR4, your 2nd wildshape can be no more than CR3, your 3rd CR2, etc.. you can continue at CR0 as long as you have time.
2. If changing wildshapes would decrease your hit points take the new hit points, if changing wildshapes would increase your hitpoints, take the average (round down) of the two forms current and average hitpoint. 
   ex. Druid wildshapes into a pig (avg 5hp), and takes 4 damage, she has 1hp, then later she changes into a giant scorpion (avg 52hp), she has (52+1)/2=26hps. If she were further wounded to 12 and turned into an allosaurus (avg 51 hp), she have (12+51)/2=31hps. 
3. The duration of each subsequent shape is one-half the remaining duration.

* Circle of Moon = Bonus action

CR - Example Animals

• CR 6 - Mammoth
• CR 5 - Giant Crocodile, Triceratops
• CR 4 - Elephant, Stegosaurus
• CR 3 - Ankylosaurus, Giant Scorpion, Killer Whale
• CR 2 - Cave Bear, Giant Boar, Giant Elk, Rhinoceros, Saber-Toothed Tiger 
• CR 1 - Brown Bear, Dire Wolf, Giant Octopus, Giant Spider, Lion
• CR1/2 - Ape, Black Bear, Crocodile, Giant Wasp, Reef Shark, Warhorse
• CR1/4 - Boar, Elk, Giant Bat, Giant Frog, Giant Owl, Panther, Wolf
• CR 1/8 - Dolphin, Giant Rat, Giant Weasel, Mastiff, Mule, Poisonous Snake
• CR 0  - Bat, Cat, Deer, Goat, Hawk, Rat, Raven, Seal, Spider