Diddy & Dixie Barrels
From the Super Mario Wiki
This kind of Barrel can only be used by the Kong whose face is pictured on the Barrel, which means that only Diddy Kong can use the Diddy Barrel and Dixie Kong can only use the Dixie Barrel. The wrong Kong will instead pass through their friend's barrel should they come in contact with one. When the corresponding Kong jumps into their Barrel, they will be launched out automatically.
The barrels can sometimes be found at the End of Level Targets to make obtaining a prize easier.
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