Martin Chalfie never envisioned celebrating his 2008 Nobel Prize in chemistry by toting a giant paper mâché frog on his shoulders across the Stockholm University campus on a cold, dark December eve.

Nell Nere of St. Paul patches up a paper mache frog puppet on Thursday for In the Heart of the Beast Puppet and Mask Theatre's annual May Day parade and festival. "It's a fun, community event," said ...