A 39-year-old male was admitted for recurrent ischemic strokes. TEE was performed to detect the potential intra-cardiac thrombi and right-to-left shunts. A large hypermobile, echodense, irregular mass was found in the right atrium, which looked like a cluster of grapes. The motion of the components of the mass was synchronized, prolapsing into right ventricle in an octopus-like fashion during diastole. There was no evidence for PFO or other intra-cardiac shunts by color flow Doppler. The patient was referred to surgery and a continuous 30 cm long thrombus spanning from the inferior vena cava to the right ventricle was discovered.