Saccharomycopsis yeasts form—together with species of the genus Ascoidea—a CTG clade within the Ascoideales. Both genera are separated from other yeasts by their uncommon genetic code translating the CUG codon into serine instead of leucine. In addition, the majority of Saccharomycopsis species are predator yeastspredator yeasts. Among them, Saccharomycopsis schoenii has attained a worldwide distribution and gained attention as a model predator yeastpredator yeast. PredationPredation is the ability to attack and kill fungal prey cells using a specialized invasion structure, the penetration pegpenetration peg. This behavior can be induced by starvationstarvation, particularly by methionine deprivation, and comparative genomics indicated that predator yeasts are natural organic sulfur auxotrophs. Using time-lapse fluorescence microscopy, we characterized Saccharomycopsis schoenii predation events from the initial formation of a penetration peg to the killing of Saccharomyces cerevisiae prey cells. Molecular genetic studies identified the MAP kinaseMAP kinase Kil1Kil1, encoded by a homolog of the Saccharomyces cerevisiae FUS3/KSS1 genes, and the transcription factor Ste12Ste12 as central pathogenicity genes. Kil1 and Ste12 regulate a set of predation response genespredation response genes and govern penetration peg formation. Predator yeasts such as Saccharomycopsis schoenii thus present a unique and powerful eukaryotic model system to investigate predation and predator-prey interactions, particularly with Saccharomyces cerevisiae as prey cells, both at the molecular and cellular levels.