Images of the historical Buddha (born as Siddhartha Gautama) are part of every Buddhist tradition.  Other figures that are part of some Buddhist traditions include:

• Bodhisattvas.  People whose karma was so elevated that they could have passed to Nirvana, but instead chose to remain in this world out of compassion for other human beings.  They may be able to offer assistance or comfort to people in suffering.  The most widely known and represented Bodhisattva is Avalokiteshvara, represented in female form in Tibetan tradition as Tara, in Chinese tradition as Kuan Yin (or Guan Yin or Kwan Yin), and in Japanese tradition as Kannon.
• the "Laughing Buddha."  A folk figure of an itinerant Chinese monk named Ho-tei is widely referred to by non-Buddhists as the "laughing Buddha" or "happy Buddha."  According to some beliefs he is an incarnation of a Buddha who will appear in the future and might properly be called a bodhisattva.
• Monks and teachers.  All Buddhist traditions offer great respect to the monks who give their lives to perfection of virtue and work for the education and enlightenment of all of us.  In Mahayana tradition images are often made to honor famous teachers.  The most basic Buddhist prayer is: I take refuge in the Buddha, the Dharma (Buddha's teaching) and the Sangha (the community of Buddhist monks).