A “spoonerism” is where the letters or sounds of two words in a phrase are swapped eg: a “sad ballad” becomes a “bad salad”, or “take a shower” becomes “shake a tower”. It’s named after Reverend Archibald Spooner (1844-1939), who was an English language scholar at Oxford who apparently had a habit of accidentally mixing up words on this way (“kinkering kongs” instead of conquering kings”). It’s a common cryptic technique, indicated by a reference to spooner or sometimes by the word spoon or spooned.
The quintessential vampire is Count Dracula, or (on Sesame Street), The Count.
So Count Molar becomes Mount Colah.