Its the ball at the endog a railing or bannister. It's put there either for decorative purposes or to prevent children (or myself) from sliding down them.
Not even the first to have this particular implant there was a similar operation done in Montreal (Canada) bout 6 years ago, he was the first north American to not have a pulse, but the technique and implant were pioneered in Europe I think http://www.cbc.ca/news/health/story/2006/12/13/mechanical-heart.html
They are actually the eggs of a very rare type of frog long thought to be extinct. Species name Caelum rana. Glad to see reports of its demise we're greatly exaggerated.
2) Powered by caffeine, L, black
3) Monster feet slippers