Tadpole looks like the animal tadpole but in the Underworld, they are used to communicate. The ones who seem to use them are the Legislator, Executive and presumably Justice.
Different Tadpoles[]
Rippō (The Legislator)[]
This is the Legislator's Tadpole in the manga
This is the Legislator's Tadpole in the anime
Gyōsei (The Executive)[]
This is the Executive's Tadpole in the manga
This is the Executive's Tadpole in the anime
Shihō (The Justice)[]
No picture of the tadpole yet since it hasn't been seen in the manga yet.