This is my attempt at making a (very) budget defender deck.

Every creature in this deck has defender. It's very important to have assault formation in your opening hand, though it is possible for the deck to work if you don't.

Get as many defenders as you can onto the field and then use Axebane Guardian and Overgrown Battlement to mana ramp and easily pay for Colossus of Akros and make him monstrous.

Tower Defense is also a fun card to use if you have an Assault Formation on the field.

Use Sheltering Word on either Tree of Redemption, Colossus of Akros, or Ludevic's Abomination (and preferably after playing a Tower Defense.)

Add hatchling counters to Ludevic's Test Subject whenever you can, which shouldn't be difficult if you have mana ramps on the battlefield. You might be able to transform Ludevic's Test Subject the same turn you play it.

Let me know what you think!