Because "transmogrify" has "mog" in it, I thought it meant "to swap cats".
A childhood belief about cats and dogs

others believed things like this
- When I was a little kid i thought cattle meant a group of cats— It's a group of cows and bulls!
- When my brother was 5 I use to swap a $5.00 note for lots of coins because he thought that I had more money— MATT NEWTON
- My sister and I thought cats and dogs were the same animal, the dogs were male and the cats were female.— Paul
- i beleived that when someone bought a new house, they would swap with the person they bought it from— c
- I alwaysused to think white cats were girls, and black cats were male ...— Smiley Face
- I used to believe that the cats eyes in the road...reflectors...were the eyeballs from real cats.— Liza P.