This one originates from one of Team Rocket's mechs, a giant Meowth that fired blasts of gum. I have no idea how they thought that would be practical, but it was a rather throwaway episode (aside from it being the one where Ash gets Cyndaquil) so whatever. I guess that's technically the second ballpit belly too despite this guy being like a gumball machine.

Four more still on the backlog~