She is described by her own Flame Haze as a most unsociable entity; she is taciturn and to the point, saying nothing more than what is necessary, usually in monotone, betraying no emotion regardless of the situation, a trait not unlike Wilhelmina herself, who is also a person of few words and often speaks in a monotonous manner while usually sporting a deadpan face. However, while in the final battle at Misaki City, she conversed with Wilhelmina in full sentences, using the same "de-arimasu" ending to her sentences that Wilhelmina uses. Along with Wilhelmina's "Dancing Princess of Peerless Combatant Skills", she also has a nickname, "Great River of Reticence" (寡言の大河 Kagen no Taiga ), which is sometimes shortened to just "Reticence".
- Her name refers to a primordial goddess from Babylonian mythology.
- The name of her Vessel can be taken to mean many things, but in Latin it refers to a theatrical mask.
- In the novels, her lines are almost always written in four kanji letters, with no hiragana or katakana.
- Along with Wilhelmina's "Dancing Princess of Peerless Combatant Skills", Tiamat has the nickname "Great River of Reticence."