The paper offers a new approach to the debated issue of the relationship between the two Lives of St Ioannikios (d. 846) both written by his contemporaries. A prominent place in the two texts belongs to the motif of dragon fi ghting (or taming) where dragons are clearly mythical creatures. In the Life by Peter (BHG 936) the relationship of the saint with dragons and an aspid forms an organic part of a certain conception linking together beasts, serpents and demons with which Ioannikios interacts in different ways, whereas in Sabas’ biography (BHG 935) the topic looks simplifi ed and not conceptually relevant. This conclusion makes it more probable that Sabas used Peter as (the main) source, disregarding at the same time Peter’s complex views on the role of mythical and real serpents as partners or adversaries of the main hero.