Dr. Pentangeli

Dr. Pentangeli was the doctor for the Medici family who lived on the Via Montebello. He became embroiled in Piero de' Medici's schemes and, ultimately, paid the price.

Biography
Pentangeli had been the Medici family doctor for as long as Lorenzo de' Medici could remember. He had been supplying ointment to Lorenzo de' Medici for an unknown swelling. (The Mask of Death)

He tended to the Duke of Florence when he was shot by an arrow during an attempted assassination. (Dragon Hunt)

When Leonardo da Vinci discovered the Duke had been poisoned with Cyanide, he asked Lorenzo to take him to Dr. Pentangeli's home to discuss some "physiological phenomena". Pentageli appears to be impressed with Leo and tells him they will do a post mortem to find out the truth. However, it's soon clear that Pentangeli is in league with Piero and that it was him to provided him with the poison. Pentangeli panics that Leo will expose them and tells Piero they need to kill him and Piero appears to agree. However, at the post mortem, Scarpa, the assasin, arrives and although it looks as though he will shoot Leo, to Pentangeli's shock, he turns to him and fires. As Pentangeli as breathes his last, he stutters "M-" (for Medici) before dying. Leo interprets this as "Milanese" and after fining cyanide on the arrow assumes that the Milanese dip their arrows in poison to ensure their targets die. (The Mask of Death)

Personality
As a doctor, Pentangeli was an intellectual who had access to an array of dangerous substances, namely the Cyanide. Although on the surface, he appeared to be a nice man, he was revealed to be extremely treacherous, assisting Piero with the murder of the duke, and was extremely two-faced, earning Leonardo's trust and pushing for his murder moments later. He was also sickeningly smug that Leonardo was being led to his death. His arrogance and loyalty to Piero, however, cost him his life as he underestimated how far he would go to maintain his plans.