The thing that one can catch
but cannot throw is a Cold.

Detailed answer:
We all know that when we feel sick, we usually say that we caught a cold due to a bad weather or due to getting soaked in the rain. But we never hear that someone throw the cold.

So, a cold can be caught, or a person can catch a cold.
But we know that cold can’t be thrown to someone else as it cannot be transmitted like that.
For example: After spending a lot of time playing in the water, Rohan had a cold, but he cannot throw this cold to his friends.
Here, the term “cold” refers to the state of being unwell and having a runny nose (Nasal fluids).