Calvin's throat froggy

Calvin has a persistent cough right now.  Dave has him convinced that a froggy is living in his throat!  A couple days ago when I was picking Violet up from preschool, he was in the van with me and started coughing.  He said "I don't know what the proggy is doing in dere.  Maybe he is hopping around!"  He keeps asking to go to the doctor so he can feel better, but I'm not going to take him.