My object cannot be initialized because of the "else if" loop for some reason

I'm trying to add three kinds of monsters into an array by initializing my Monster-object based on the modulo. (I'm just a beginner so bare with me).

for (int i=0; i<nrofMonsters; i++) {
    Monster m;
    if (i%2==0) { 
        m = new Vampire("Vamp-"+i);
    } else if(i%2==1) {
        m = new Ghost("Ghost-"+i);
    } else if(i%3==2){
        m = new Demon("Demon-"+i);
    }
    monsters.add(m);
}

ERROR MESSAGE: variable m might not have been initialized.