To clarify that: fish is sufficient. One does not have to eat land animals.
Confirm. I'll add that the creatine content in fish is far more variable (by species) than in land mammals and is typically much lower (~1/2). But if you stick to Herring you'll be laughing! (Ref).
I'm looking for resources on effective weight training for the purpose of physique building. It's an area with a particularly poor signal to noise ratio so I would value pointers from other rationalists. The kinds of questions I would like to answer are:
Edit: I'm vegetarian, and I now realise this is rather important to answers to point three. So far the only supplement I've been taking is soy protein.