We named it ‘The Crazy Cow’! Why?  The reason is my children just bounce like crazy, especially my son! When we first got happy hopperz cow, it is very simply to use.  No instruction is included, and is not necessary as it’s very self explanatory).  After foot pumping for 5 minutes (foot pump not included) we had a fully inflated cow!  The stopper plug is well designed in that it is very hard for the children to pull out once full inflated.