Any person who does an act which is not justified and which is intended to cause serious injury to another commits willful injury, which is punishable as follows:
1. A class “C” felony, if the person causes serious injury to another.
2. A class “D” felony, if the person causes bodily injury to another.
99 Acts, ch 65, §5; 2013 Acts, ch 90, §184
Serious injury, §702.18