Plenty of chemists jars with spooky labels instead of actual spirit bottles. Gin could become Vir-gin Tears etc You can always decant what's left (if any) back into the original bottles after the party has finished.
Possibly use dry ice donated by the chemistry department. Serve drinks in triangular shaped beakers, couple of bunsen burners on the go etc
The Dr Pumpkinstein pattern would fit in well of course.