Board Thread:Theories and Speculation/@comment-45444155-20200728155230/@comment-32685487-20200731221153

I think Jiraiya was imperfect because he could not use Sage Mode without Fukasaku and Shima, another words he couldn't really do it on his own. I think he took on toadlike features because he had Fukasaku and Shima fused to his body.