Toadpoli

Toadpolis are enemies appearing in Twilight Princess and Link's Crossbow Training.

Characteristics
They appear as frogs but act very similarly to Octoroks seen in previous 3D Zelda games.

They appear as armored, two-legged frogs who have retained their caudal fins. A universal trait of all Toadpolis is that they spit balls at Link, which he must deflect. If the young hero comes too close to them, they will dive back under whatever they're swimming in.

Variations
There are multiple variations of Toadpolis:

Water Toadpoli
Water Toadpolis can be found in swimming in water in the Goron Mines and behind the Howling Stone in Lake Hylia. They spit rocks at the young hero that can be deflected with a shield. In Link's Crossbow Training, Water Toadpolis appear in the Rapids Ride level.

Fire Toadpoli
Fire Toadpolis can be found early on in the Goron Mines, swimming in lava. They spit molten rock at Link that can burn his Ordon Shield or Wooden Shield. The molten balls in can be sliced with the sword and be deflected back at the Fire Toadpoli, killing it.

Trivia

 * Many believed that Toadpolis were actually Octoroks in Twilight Princess.
 * Toadpolis also bear an appearance and similar attacks as Zoras in the original The Legend of Zelda, and Link's Awakening. They also share some physical similarities to the Deku Toad.
 * Their name may be a combination of the word toad and the word polliwog, which is a synonym for tadpole.
 * Both the name and anatomy of Toadpolis seem to imply they're still in a stage of metamorphosis, which may explain their physical similarities with the Deku Toad. According to Hyrule Historia, "the Deku Toad was meant to depict what a Toadpoli might look like a thousand years in the future."