Bug Summon drop loot and xp

function onCastSpell(creature, variant)
    if creature:getSkull() == SKULL_BLACK then
        creature:sendCancelMessage(RETURNVALUE_NOTPOSSIBLE)
        return false
    end

    local monsterName = variant:getString()
    local monsterType = MonsterType(monsterName)

    if not monsterType then
        creature:sendCancelMessage(RETURNVALUE_NOTPOSSIBLE)
        creature:getPosition():sendMagicEffect(CONST_ME_POFF)...