a spooner
A spooner is a clueless poser who thinks they're smart but are just a brain-dead joker.
My teacher said I made a spoonerism when I said 'flishy wash' instead of 'wishy wash'
My friend called his dog 'biscuit cat' and it was the worst spoonerism ever
My mom said 'shat on me' instead of 'chat on me' and I laughed so hard I cried