Did Mekdawa ask you "You know what Ukabu mean?"
Answering him "No" if he has never told you before will prompt him to give you the quest to go see Shinwiki, telling Ekbu (the first Toad Guard in the Toad Village hut) "Ukabu" so that you may pass safely by the other toads on your way to Shinwiki's hut.
Some toads may get in your way in the tunnels...the one in the water you may have to kill but most of them do respond to the word "Hail" and will follow you, allowing you to lead them back to a place where you may turn around and go around them.
Moni