Globular cluster
Every galaxy of sufficient mass in the Local Group has its group of globular clusters, and almost every large galaxy surveyed has  a system of globular clusters. The Sagittarius Dwarf and Canis Major Dwarf galaxies appear to be in the process of donating their associated globular clusters (such as Palomar 12) to the Milky Way. This demonstrates how many of this galaxy's globular clusters might have been acquired in the past.