I think you probably know this, but whey is suitable for vegetarians (being a byproduct of curdling milk) - and whey-based protein supplements are often vegetarian. Vegan protein supplements are generally extracted from things like peas, beans or hemp.
I do know that, but thanks for clarifying. The word vegetarian in this case refers to being composed of only plant products. Maybe it can't be used that way.
Both are substantially lower impact than meat protein.