GURPS Supplements using two cows

[Dwarf99]

Someone had one on RPG books in general, but I recently decided (rather than necro that thread which is who knows how old) to start a new one on GURPS supplements exclusively. Basically two cows is a metaphor for explaining something. So being the thread starter, I'll start

GURPS Basic Set: You have 2 cows. They're pretty plain and generic, but they leave you wanting more
GURPS Bio Tech: You have two cows, but growth hormones allow them the output of six cows.
GURPS Powers: You have 2 cows. One has laser eyes, the other has Winged Flight
GURPS High Tech: You had two cows. One of them was shot with a Winchester Mod. 700.
GURPS Dungeon Fantasy: The Lord of the Infernal Pastures has two cows. You must milk them, kill the Infernal Lord and take his stuff.
GURPS Thaumatology: You have two cow familiars. One of them grants you Unlimited Mana, and the other allows you vast control over powerful Realms of magic.
GURPS Action: Holy crap! That cow just ran a motorcycle into a helicopter!
GURPS Martial Arts: Before you learn Karate grasshoppa, you must first learn Milk the Cow.

[Phantasm]

GURPS Fantasy - You have two cows; one is a powerful barbarian spellsword, the other is just a cow.
GURPS Space - You have two cows. One is an alien, but ... which one?

[johndallman]

GURPS In Nomine: There are two cows. One is a Hellcow, the other is an agent of the Hindu gods.

[ericthered]

GURPS Low Tech companion 1: Philosphers and Kings: you have two cows, but only if you go to war 60 days a year, and if the priests don't need to sacrifice it.
GURPS Low Tech companion 2: Weapons and Warriors: You have two cows. You hook them up to a cart and use them to move grain to feed more soldiers than your enemies.
GURPS Low Tech companion 3: Daily Life and Economics: You have two cows. They eat food and produce milk. Read more to find out exactly how much.

[Anaraxes]

GURPS Transbovine Space - You have two cows, but seven bodies of three different categories and nine intelligences of varying degrees.

[Randyman]

GURPS Monster Hunters: You have two cows. One is a Hindu Angel, the other is a werecow.

[ericthered]

Gurps 3e Fantasy II: the madlands: You have two cows. One of them is a milkless, the other is a mooless. Both are dangerous monsters and you should run away.

[PK]

GURPS Social Engineering: You have two cows. You negotiate with your neighbor to borrow his bull in exchange for milk, breed several calves, then embark on an advertising campaign to raise their value before selling them.

[David Johnston2]

GURPS Social Engineering: You have two cows. Fortunately you have Animal Empathy so you can use your Sex Appeal.

[Agemegos]

GURPS VDS for 4e: "for simplicity, imagine a spherical cow".