L'avvelenato (The poisoned man), or Il testamento dell'Avvelenato (The will of the poisoned man), is an Italian ballad attested for the first time in a repertoire of popular songs published in 1629 in Verona by a Florentine, Camillo the Bianchino. It was then also reproduced by Alessandro d'Ancona in his essay "La poesia popolare italiana': the author expresses the opinion that the original text was Tuscan and contains some versions from the Como area and Lucca. Translated in Folk-ballads of Southern Europe edited by Sophie Jewett, Katharine Lee Bates, 1913.
To date there are almost 200 regional versions of this ballad, based on the dialogue between mother (or sometimes the wife) and son who in some regions is called Henry, in other Peppino in others, as in Canton Ticino, Guerino: other characters are the doctor, the confessor and the notary, only in the final we learn that his wife is the guilty (in some versions the sister or more rarely the mother)
see lyrics and translations in https://terreceltiche.altervista.org/il-testamento-dellavvelenato-2/