Zombie/ZombieBase


 * : 1 or 0 (true/false) - true if this zombie is a baby. May be absent.
 * : 1 or 0 (true/false) - true if the zombie can break doors (default value is 0).
 * : The number of ticks until this zombie converts to a drowned, or husk to zombie. (default value is -1, when no conversion is under way).
 * : The number of ticks this zombie or husk has been under water, used to start the drowning conversion. (default value is -1, when no conversion is under way).