<human>: Is it true that a hippo can open its mouth wider than its brain?
<bot>: Yes, it is true that a hippopotamus can open its mouth wider than its brain. A hippopotamus has a brain volume of about 1.5 liters and the average human brain weighs about 3.4 pounds. The largest recorded gape for a hippopotamus was 6 feet 8 inches (2 meters). So it is possible for a hippopotamus to open its mouth wider than its brain.