Metathesis is phonological process that switches the order of phonemes in an individual word. Metathesis can also occur across corresponding words and this is commonly know as a Spoonerism. The process was named after Reverend William Archibald Spooner (1844 - 1930)who was known for his very frequent slips of the tongue.
Bass ackwards, chilled greese, hot poles, cop porn
One of my favorites is - "no bout adoubt it"
A bumper sticker on a car - "Juck Fapan"