SB 10.18.21
acerur vividhah krida
vahya-vahaka-laksanah
yatrarohanti jetaro
vahanti ca parajitah
Translation:
The boys played various games involving carriers and passengers. In these games the winners would climb up on the backs of the losers, who would have to carry them.
Purport:
Srila Sanatana Gosvami quotes the following relevant verse from the Visnu Purana (5.9.12):
harinakridanam nama
bala-kridanakam tatah
prakridata hi te sarve
dvau dvau yugapad utpatan
“They then played the childhood game known as harinakridanam, in which each boy paired off with an opponent and all the boys simultaneously attacked their respective rivals.”