How do i say "vegan" in mandarin ?
不要猪肉好。我是...
I want to be able to let people know that i am vegan when i
make my order in a chinese restaurant.

Question

How do i say "vegan" in mandarin ?
不要猪肉好。 我是...
I want to be able to let people know that i am vegan when i 
make my order in a chinese restaurant.

Answer

Vegan="素食主义者"，
I suggest you say"我不吃肉"， it's simple and clear.
Also, make sure if they use pig fat to cook. “请问你们用的是猪油吗？”

Answer

You can say "我吃素”

Answer

As far as I know, vegans are different from vegetarians or veggies. Thus, you'd better say, "我吃"全"素。" and then they wouldn't serve you meals with eggs, dairy food, and meat, etc.