Can you chain Night Caller whistlers?

Question

You, a 13th-level wizard, go to a graveyard and blow your Night Caller. Then you cast Awaken Undead on the zombie, and one week later have it blow on the Night Caller and order the new zombie to obey you.

Can you just keep going with this over the course of a year like some unholy pyramid scheme to let you have more zombies than Animate Dead would allow?

Answer 1

Yes, but it's not really worth it

For one thing, you'll pay 200xp per casting of awaken undead. Also, zombies won't be very useful in combat once you're thirteenth level.

If you want a pyramid of commanded undead, one good way to accomplish that is to gain control of a shadow, which has this power:

Any humanoid reduced to Strength 0 by a shadow becomes a shadow under the control of its killer within 1d4 rounds.

Some other types of undead can do this too. Vampires will work, for example, if you have access to creatures that can turn into them.

Note that all of these pyramid plans are sort of irresponsible, because if one of your top-level undead gets destroyed, the rest go free.

Answer 2

No

There's two simple reasons for this:

1. Undead do not breathe. I doubt that RAW says that this prevents them from blowing a whistle, but I doubt you'll find a DM who'll let that fly.
2. You will eventually run out of graves.