There's not a googol of anything physical in the universe. On the other hand, numbers larger than a googol routinely arise in application. When you're counting potential things rather than physical things you can run into numbers much larger than a googol. This happens all the time in probability calculations.

Is there anything that is a googolplex?

Googolplex. If you fill the entire observable universe with fine dust particles around 1.5 micrometers big, the total number of combinations in which these particles can be arranged is equal to one googolplex, according to astronomer and astrophysicist Carl Sagan.

Does the number googolplex exist?

A googolplex is the number 10^googol, or equivalently, 10. ... Written out in ordinary decimal notation, it is 1 followed by 10¹⁰⁰ zeroes; that is, a 1 followed by a googol zeroes.