No, a foreign key constraint always references exactly one parent table.
This question comes up frequently. Here are some of my past answers to it:
- Why can you not have a foreign key in a polymorphic association?
- Possible to do a MySQL foreign key to one of two possible tables?
- Referencing foreign keys in the same column
- In a StackOverflow clone, what relationship should a Comments table have to Questions and Answers?
- MySQL – Conditional Foreign Key Constraints
- How to handle an “OR” relationship in an ERD (table) design?
- MySQL: Two n:1 relations, but not both at once
For more on Polymorphic Associations, see my presentation Practical Object-Oriented Models in SQL or my book, SQL Antipatterns, Volume 1: Avoiding the Pitfalls of Database Programming.