Zebra.
"Splenic rupture is usually precipitated by a crushing injury or severe blow. Much less often, it occurs in the apparent absence of trauma. Such "spontaneous ruptures" never occur in truly normal spleens, but rather stem from some minor physical insult to a spleen that has been rendered fragile by an underlying condition. The most common predisposing conditions are infectious mononucleosis, malaria, typhoid fever, and lymphoid neoplasms. "