Jak dodac zmienna do moba

Witam! Czy ktoś wie jak dodać zmienna do moba? (hp wirtualnego)
i zeby co atak oddejmowalo 20 i zeby zginal dopiero gdy zmienna hp spadnie do 0

narazie mam cos takiego
 

every 10 second:
    if {spawn1moba} is not set:
        set {spawn1moba} to 0
    if {spawn1moba} < 3:
        spawn 1 zombie at {spawnmobka}
        heal last spawned entity
        set the spawned zombie's display name to "&fSlaby Ork &cLv. &21"
        set helmet of last spawned entity to diamond helmet