This was renowned as the best of the 3 virtually interchangeable vampire 'classics' emanating from Italy early into their Gothic Horror phase; however, while that may be so, it is still nothing to write home about! I am not sure about THE VAMPIRE AND THE BALLERINA (1960) since it has been some time from my sole viewing of it, but this at least maintains a period setting throughout (beginning with villagers rising up against a bloodsucking couple). Incidentally, while Walter Brandi also turns up here, he is not the monster – the latter, in fact, is played by Dieter Eppler and he proves one of the hammiest ever depicted, while hilariously looking like Criswell from the Ed Wood movies! Brandi, then, makes for an ineffectual lead (he is even bitten twice throughout, offering virtually no opposition to his female assailants!) – though he does contrive to ambiguously participate in the climax, where we are unsure whether he intends harming a little girl or not, before trapping Eppler and proceeding to impale him with the pointed edges of a wooden gate!
During the course of the film, Eppler manages to vampirize two ladies: Brandi's wife Graziella Granata (who is virtually put under a spell by the villain, whose coffin is hidden in their country-estate's wine-cellar!) – an unintentionally amusing scene has her responding to Eppler's disembodied voice, then he nonchalantly appears from behind a nearby tree! – and her maid (who looks an awful lot like a plumper version of Isabelle Adjani!). The most impressive member of the cast is Paolo Solvay, actually a pseudonym for director Luigi Batzella (best-known for the nonsensical erotic Gothic NUDE FOR Satan [1974]), here appearing as Dr. Nietzche(!) and evoking Peter Cook, of all people, in appearance – in his case, the most hilarious bit has him telling Brandi of Granata's imminent demise and getting no reaction whatsoever (incidentally, the English dialogue of this one is exceedingly stilted, which may well have been an intentional choice so as to complement Eppler's stagy performance)! Another future film-maker, Alfredo Rizzo, turns up here as well but in a minor role this time around.
In conclusion, I recently watched an interview with director Mauri on the "Stracult" program on late-night Italian TV: apart from SLAUGHTER itself (in Italian), this section included scenes from a number of his other efforts
and I was sufficiently intrigued to acquire the black-and-white Giallo NIGHT OF VIOLENCE (1965), the psycho-drama MADELINE, STUDY OF A NIGHTMARE (1974; with Camille Keaton, and whose failure through poor distribution Mauri particularly bemoaned) and THE PORNO KILLERS (1980; albeit in its softer original form) soon after!