Board Thread:Theories and Speculation/@comment-35051547-20180320000346/@comment-734582-20180321090557

Namikazenaruto9 wrote: It implied by Shizune in 4th great ninja war that 100 seals is required to summon Katsuyu the only thing she fails in her training with lady tsunade. I don't think so. The main benefit of Katsuyu is that she can split and heal dozens of people based upon how much chakra she gets. I think it's more that without the seal, none of the three have enough chakra to really make use of her. Basically, what's the point of summoning one tiny slug who may heal a bit? Namikazenaruto9 wrote: Read Frog Sage mode again. What part? The part you wrote? on the wiki? in the manga?

Nature energy simply transforms you into whatever animal you got connected with. Kabuto is a snake sage, so he has snake features. Jiraiya is a toad sage, and has toad features. If you steal this energy, the animal part carries on (Preta turns to a Frog). Juugo's KKG specifically allows free-form transformation, which is where the confusion comes from. Orochimaru apparently experimented to evoke various animals (Seal of Heaven gives flight, for instance).

According to Databook 4, the Snakes learn it by injecting the body with Nature energy. Not enzymes like Juugo's which allow for this transformation.