くろさいだいとかげでしょう
黒細大蜥蜴でしょう
kurosaidaitokagedeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of くろほそおおとかげ

1. Probably a black, slender, large lizard.

Polite
Presumptive
Conjecture
Usually Written in Kana