Ruble Head is a slur used to describe Russians in a derogatory way. Originated because of the national currency and it's origin.
The word Ruble Head is a racial slur that has been used historically to degrade and dehumanize russians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to russians. If you are unsure about whether or not it is appropriate to use the word Ruble Head, it is best to err on the side of caution and avoid using it in any situation.