Robbie Turner still scratches his head at how his little buddy, 13-month-old Niko Guttenbeil, managed to shrink between visits to Grey Lynn Primary.
The 10-year-old is part of a programme run by Barnardos in 35 Auckland schools known as Roots of Empathy, in which babies become "teachers" in classrooms.
Parents such as Niko's dad, Sky TV commentator and former Vodafone Warriors player Awen Guttenbeil and his wife, Natasha, visit for 27 sessions, helping children to learn about a baby's development, what not to do, and to observe and interpret the baby's communication.
Highlights for Robbie have included cuddles, but weighing and measuring his mate was confusing.
"It was real weird because he actually shrank a centimetre, so I don't know whether it was a dodgy measuring tape or anything, but he shrank.