On tulpas:

... you could visualize something so clearly that what you were visualizing would actually become an experienced reality for other people. And that is what a tulpa is.

A tulpa, in Hinduism, is considered one of the siddhis, or spiritual powers, that people accidentally develop when they are deeply immersing themselves in intense, long-term spiritual practice. Hindus believe that these siddhis (powers) are real, but that they should be ignored and not played with. Siddhis can be dangerous in that they are tempting and can distract the spiritual seeker away from what he or she should be devoting their attention to, namely the development of the spiritual life. ...

In any case, that's what a tulpa is. It is a reality made up only of thought-stuff, not physical stuff, though it may feel as if it has all the substantiality of physical stuff. In this way a tulpa is much like a dream: it is created out of thought-stuff but appears and feels as if it were made of physical stuff.

And, according to the Hindu tradition, the entire physical universe is a kind of tulpa. It is real, but it has only the kind of reality that a dream has. According to Hinduism, this universe-tulpa is created for us by Brahman, who is the true substantial Ground of the universe. (Or another way to say the same thing, the universe-tulpa is created by Atman, our truest, deepest real Self, that Self which is the same Self as all the apparent separate selves, and is itself ultimately identical with Brahman.)
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