its the GBA action replay that u need. you can buy one at ebgames or gamestop.
or u could download it off chao planet or use an action replay to get 1. i have the action replay code for a tails chao along with the codes for knuckles chao, amy chao, walking egg chao, and omochao in my chao faq posted on this site. the only way to get the knuckles chao, amy chao, walking egg chao, or omochao is to use the AR codes in my faq or download them off chaoplanet.
he cant mate because he is a chaos chao. chaos chao can never die but can never mate.