- "Time to earn my keep."
- —Tanu in Keys to the Demon Prison
In the Series
In Rise of the Evening Star, he was brought in to help recover the artifact from Fablehaven with Coulter Dixon and Vanessa Santoro. To demonstrate his Potions abilities, he gives Seth a mild fear Potion and Kendra a mild shame Potion when he was introducing them to his work. When Vanessa is revealed as a traitor, she knocks Tanu unconscious with a sleeping dart so that she can gain control over him. She then uses him to help capture Stan and Ruth, and later sends him into the Grove where the Revenant lives. He is turned into an albino just as Warren and Coulter were. After Seth defeated the Revenant, and Tanu is healed, he goes to the Inverted Tower just as Warren and Vanessa were about to be defeated by the Black Cat Guardian. Tanu drinks his Enlarger Potion and battles the Cat Guardian, killing it. He sustained serious injuries, but was healed by the recharged Sands of Sanctity.
In Grip of the Shadow Plague, he attempts to rescue Maddox from the preserve Rio Branco in Brazil but fails. He is bitten by a darkened Satyr, Newel, during a fight and he turns into a shadow. He can only be seen by Seth when he in this form because Seth has dark marks left by the nail from the Revenant. Seth learns that Tanu can only talk to him when the sun is setting because when in his shadow form, Tanu is burned by the light. Once the Shadow Plague is destroyed, he returns to normal.
In Secrets of the Dragon Sanctuary, Tanu is seen more as a healer in this book. He somewhat healed Warren in the Knapsack and under Vanessa's control, he slew Glommus, a sleep-infusing Dragon, inside the Dragon Temple.
In Wrath of the Dragon King, Tanu comes to Wyrmroost to assist Kendra and Seth. He goes to the Feast of Welcome with them, using a Potion of Courage to withstand the Dragon terror. After Madrigus is killed, Tanu snatches some of the Dragons organs to make Potions with. When his Griffin Titan is killed, he, Kendra, and Seth makes their way down Skyhold on the Safe Road. He manages to get to Terrabelle with the Somber Knight and later escapes to the Zowali Protectorate. Inside of Stormguard Castle, he is turned to silver, but should be normal agains since the contest there is over.
- Energizing Potions
- Enlarer Potions
- Fire-Resistant Potion
- Gaseous-State Potions
- Potions of Emotion
- Shrinking Potion