I would avoid any plants of the family Araceae, Aroids when dealing with herbivoures or omnivores. Aroids contain calcium oxalate crystals which when in contact with wounds, or skin like the inside of the mouth, can cause damage. The crystals actually destroy your cells. Your turtle will most likely survive the experience and never touch the plant ever again, but why put it through such an experience. The calcium oxalate is found in the milky sap in Aroids and other plants I believe. Its why they tell you not to have certain kinds of plants when you have dogs and cats. Some people can't even touch the milky sap because they are too sensative to it. Luckyly not me

I love Aroids!
As for frogs, I keeps lots of different kinds of Aroids in my frog tanks. No problems from anyone, so long as you don't purpusefully bread a leaf and drip the sap on your frogs on purpose, everyone should be fine. If you go in there to trim the plants, the sap dries very fast, and what are the chances the frogs will decide to sit on the wounded plant, at the site of the wound?