When a supercharged creeper explodes in a group of Zombies (anywhere from 1 - 20 have been tested) only every one head drops. Same with skeletons.
Environment
System.getProperty('os.name') == 'Linux'
System.getProperty('os.version') == '3.12.17-KAA'
System.getProperty('os.arch') == 'amd64'
System.getProperty('java.version') == '1.6.0_31'
System.getProperty('java.vendor') == 'Sun Microsystems Inc.'
System.getProperty('sun.arch.data.model') == '64'
Dupe of MC-63534