Bazyliszek is a Polish name for the basilisk, in Greek and European bestiaries and legends, a legendary reptile reputed to be king of serpents and said to have the power of causing death by a single glance.
In common language we also use the phrase "wzrok bazyliszka", the basilisk's glance which means a glance which kills.
There is a medieval legend about a Warsaw Bazyliszek - if interested see here:
http://www.warsawtour.pl/en/warsaw-for-everyone/for-kids/warsaw-legends-3160.html?page=0,1