While on holiday Jenny Harris and her brother Rex enter a mysterious cave, when Jenny speaks out of turn, Rex turns into a dog! He continues to turning from boy to dog while they try to figure out how to cure him.
While Rex solves his dog problem in a sequel You Little Monkey! , Rex tries on a circus witch-doctor’s monkey mask. From then on he keeps turning into a chimp – usually at the worst possible times!
- My Brother Rex – Mandy :#506 (25 September 1976) – (?)
- You Little Monkey! – Mandy: #612 (07 October 1978) – #623 (23 December 1978)
- My Brother Rex – Mandy Annual 1979
- You Little Monkey! – Mandy Annual 1981