In Donkey Kong Country you have these animal helpers that you can ride, which kind of give a little variety to Donkey Kong's banana-hunting exploits. And each of those animals has their own bonus stage where you have to collect lots of emblems that look like the animal that you're riding.
But getting there takes a lot of work, and they're kind of rare. So you may not be as practiced as you want to be when it's Game Time(tm).
So what do you do?
Well, you could go to the Intro sequence.
Grab Controller 1 and press Down, Y, Down, Down, Y (which, if you write 'D' instead of 'Down' spells 'DYDDY', which kind of looks like 'Diddy')
Done right, you'll be taken to a cave full of complete sets of the Animal Emblems
From there you just collect the complete set and begin your bonus stage!
And you can do this as often as you want, so practice away!