This is not the Scottish lion, as might be supposed, but the English lion as it appears on the Royal Arms of Great Britain (which appear elsewhere on the monument in Marischal (Marshal) Street in the town centre). 

The English lion and the Scottish unicorn are supporters on these arms - presumably so  because of the very important Reform Act, which changed the face of voting throughout the United Kingdom, came from Westminster, and was obviously approved by the monarch.  

The 'red rampant lion  on the golden ground' is, however, the Scottish Royal  Banner and represents Scotland when it appears on the Royal Standard.  It appears in one quarter of the Standard flown in England, but when the Queen's Royal Standard is flown within Scotland, the red rampant lion appears in two quarters."

Many thanks to Jenny Main for the above research.