Capacity: Up to 150 pounds!
Speed: 3.5 mph
Attitude: Friendly (and compliant) if treated well; stubborn if not.
Costs: $240/day (self-guided); $120/mule/day + $350/guide/day, guided, per Rock Creek Pack Station; rockcreekpackstation.com - See more at: http://www.backpacker.com/skills/beginner/packing-beginner/go-goat-mule-dog-partner-llama-packing/#sthash.fMhk4M6q.dpuf
Capacity: 80-100 pounds
Speed: 1-2 mph
Attitude: Laid-back and aloof
Costs: $65/day (self-guided) + $100 orientation + $1.25/mile truck and stock rack rental; $300-$400/day guided, per Buckhorn Llama Company;llamapack.com)
Capacity: 10 pounds (of your load); more if he's really ignorant
Speed: 2 mph
Attitude: Agreeable if well-treated, but prone to complaining
Cost: Free! Or maybe a share of the six-pack he's unknowing schlepping
Capacity: 25-50 pounds
Speed: 3 mph
Attitude: Stubborn, but once they adopt you into their herd, you're in.
Costs: $30/day/goat + $30 health certificate + $50 trailer rental, per High Uinta Pack Goats;highuintapackgoats.com
Capacity: 8-20 pounds
Speed: Your pace (2-4 mph)
Attitude: Generally spectacular
Costs: One-time investment for doggie pack ($50-$150) + roughly 12 years of subsequent TLC (you can't turn him back in after the trip)