I think that it's IsoPlayer or some object created in the IsoPlayer class, for example PlayerStatistic, but without decompiling the server or client, this object cannot be assembled. If u wanna get more information about character u may create mod in lua and write this data to a file for further processing.
for example, i wanna get how many zombies the player has killed. I can use:
local player = getSpecificPlayer(0);
local kills = player:getZombieKills();
or i wanna get how long does a character survive:
local player = getSpecificPlayer(0);
local survTime= player:getHoursSurvived();
etc...
and then use the method to write information in log file:
writeLog(filemask, message)
or parse the database, but this is a crutch....
sorry for my eng.