Sonic X #34
an issue of Sonic X by Archie Comics
Issue description
When Chris' father holds a charity auction with the top prize being a personal pool party at Thorndyke Manor, guess what egg-shaped no-goodnik places the highest bid? Sonic and Tails make the scene to make sure Eggman doesn't steal it - or more precisely, doesn't steal one of Grandpa Chuck's special motors! Hopefully Eggman won't find out that Sonic can't swim!