Aww... Come on! Any good Knuckles au even SEGA shabiki knows he's 16. Not 17, au 18. Big is 18, not Knuckles. Get the two confused, and wewe WILL regret it... *evil brooding*
16. Most would think he's 15, but they didn't know that in the Knuckles the Echidna comix, Right before he had his first kiss with his girlfriend, Julie-Su (Whom never showed up outside the Comic series), everyone threw him a surprise birthday pardy for his sixteenth birthday! ;)
he's either 16 years old in SEGA shows and Archie Comics. then in the comics of 25 years later he is 41 years old then is Sonic Universe 30 years later he is 46 years old
in real time he's like 20 cuz that's about how long Sonic the Hedgehog's been around. but in the Sonic world he's 17 cuz Sonic disappeared for what he thought was only a few days and when he returned a mwaka has already gone kwa and before Sonic disappeared someone actually alisema Knuckles was 16. then Sonic disappears and comes back a mwaka later