[u]Basic Idea[/u]
This deck started with finding Cavern Harpy and getting some ideas of how to (ab)use this card. Ally's where one of those options.

[u]Tests[/u]
The deck was tested against some of my own pauper decks, using Cockatrice or XMage. A Sideboard, even if one would have been available, was not used.
Opponent - Total number of games - Wins:
Boros Land Destruction - 7 - 4
Dimir Defensive Mill - 10 - 8
monoB control - 8 - 2
monoG stompy - 7 - 3
monoR RDW - 7 - 2
Orzhov lifegain/drain - 7 - 3
Selesnya Tokens - 7 - 5

[u]Conclusions from the tests[/u]
The deck surprised me, especially the strong mill effect from Halimar Excavator. The rest of the creatures isn't that great, but still can grow to a remarkable sice, if you get the time to do so.