I have extensive experience with the particular beheading plugin that Meep uses. We used it at spore, and it was pretty fun to tinker with. Now I'm here to tell you guys what actually works and what doesn't. All statistics are default.
Looting enchantment:
lootingrate 0.2[0.0 -> 1.0]Increases all droprates by lootingrate percent per looting level when a enchanted weapon is used
The default configuration has it set to .2. This means that a looting III sword will be 6% more likely to behead someone.
Different tools:
All tools have the same chances of beheading a player. A regular diamond sword will be just as effective has a wooden hoe.
Different locations:
Droprates are the same no matter where you are in meepcraft. The terrarium works just as well as in the wild, contrary to popular belief.
"PkOnly":
Mob heads are set to drop only when they are killed by a player. They will never drop due to natural death.
Default droprates for all available mobs:
creeperdroprate0.005[0.0 -> 1.0]Chance that a mob trophy will drop when a creeper dies
zombiedroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a zombie dies
skeletondroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a skeleton dies
witherdroprate0.025[0.0 -> 1.0]Chance that a mob trophy will drop when a wither skeleton dies
spiderdroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a spider dies
endermandroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when an enderman dies
blazedroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a blaze dies
horsedroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a horse dies
squiddroprate0.005[0.0 -> 1.0]Chance that a mob trophy will drop when a squid dies
silverfishdroprate0.005[0.0 -> 1.0]Chance that a mob trophy will drop when a silverfish dies
enderdragondroprate0.05[0.0 -> 1.0]Chance that a mob trophy will drop when an ender dragon dies
slimedroprate0.001[0.0 -> 1.0]Chance that a mob trophy will drop when a slime dies
irongolemdroprate0.005[0.0 -> 1.0]Chance that a mob trophy will drop when an iron golem dies
mushroomcowdroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a mushroom cow dies
batdroprate0.005[0.0 -> 1.0]Chance that a mob trophy will drop when a bat dies
pigzombiedroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a pig zombie dies
snowmandroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a snowman dies
ghastdroprate0.005[0.0 -> 1.0]Chance that a mob trophy will drop when a ghast dies
pigdroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a pig dies
villagerdroprate0.002[0.0 -> 1.0]Chance that a mob trophy will drop when a villager dies
The full configuration and more info on PlayerHeads can be found here.
