Eat a jellybean prior to turning into a beaver. Transform into a beaver. Notice that you're health rapidly starts to regenerate compared to normal (heart pings green two times). Transform back into Woodie and now you get three times the jellybean regen power. (I'm not sure about if the regen timer itself extends itself or not).
Spoilers contains an example of what I mean.
Eat jellybean at low health with Woodie (low HP to see yourself). Turn into beaver. See you're getting multiple green pings for health. Turn back into Woodie. See that you are now getting 3x the jellybean power.