Cranky's ability giving potions are required to recover your Golden Bananas, and to progress through the game.
All Kongs
Simian Slam (Buttus Bashum):
Price: Free
A Level 1 Ground Pound, with a small green shockwave. Lets you activate green switches. Available at DK Isles.
Super Simian Slam (Big Buttus Bashum):
Price: 5 Coins
A Level 2 Ground Pound, with a medium-sized blue shockwave. Lets you activate blue switches. Available since Fungi Forest.
Super Duper Simian Slam (Bigga Buttus Bashum):
Price: 7 Coins
A Level 3 Ground Pound, with a large red shockwave. Lets you activate red switches. Available since Creepy Castle.
DK
Baboon Blast (Barrelium Perilous)
Price: 3 Coins
Lets DK access Barrel Blast areas. Stand on the DK Pad and press 
to be launched to the Barrel Blast area. Available since Jungle Japes.
Strong Kong (Strongus Kongus)
Price: 5 Coins
Lets DK become temporarily invincible by jumping into a DK Barrel. Uses Crystal Coconuts. Available since Angry Aztec.
Gorilla Grab (Simian Strainus)
Price: 7 Coins
Lets DK pull levers. Stand on the footplate and press 
. Available since Frantic Factory.
Diddy
Chimpy Charge (Hurtus Cranium)
Price: 3 Coins
Lets Diddy charge headfirst by pressing +. Lets Diddy activate certain switches. Available since Jungle Japes.
Rocketbarrel Boost (Boostum Highum)
Price: 5 Coins
Lets Diddy use Cranky's prototype Jetbarrel by jumping into a Diddy Barrel. Press 
to fly, press to fire your Peanut Popguns, and press to hover. Available since Angry Aztec.
Simian Spring (Leapus Largium)
Price: 7 Coins
Lets Diddy jump very high by pressing on a Diddy Pad. Available since Frantic Factory.
Lanky
OrangStand (Palmus Walkum)
Price: 3 Coins
Lets Lanky do a handstand by pressing + and holding . Lets Lanky climb steep slopes. Available since Jungle Japes.
Baboon Balloon (Baboonus Balloonus)
Price: 5 Coins
Lets Lanky inflate with air to float to unreachable places by pressing on a Lanky Pad. Available since Frantic Factory.
OrangSprint (Palmus Dashium)
Price: 7 Coins
Lets Lanky run very fast on his hands by jumping into a Lanky Barrel. Uses Crystal Coconuts. Available since Crystal Caves.
Tiny
Mini-Monkey (Kongum Smallus)
Price: 3 Coins
Lets Tiny shrink in size by jumping into a Tiny Barrel. Uses Crystal Coconuts. Available since Jungle Japes.
Pony Tail Twirl (Roundum Roundus)
Price: 5 Coins
Lets Tiny hover in mid-air by pressing in the air. Available since Frantic Factory.
Monkeyport (Warpum Craftious)
Price: 7 Coins
Lets Tiny warp by pressing on a Tiny Pad. Available since Crystal Caves.
Chunky
Hunky Chunky (Kremlinus Crushum)
Price: 3 Coins
Lets Chunky grow in size by jumping into a Chunky Barrel. Uses Crystal Coconuts. Available since Jungle Japes.
Primate Punch (Sandwichium Knucklus)
Price: 5 Coins
Lets Chunky use a strong punch by pressing +. Useful in knocking down cracked doors. Available since Angry Aztec.
Gorilla Gone (Whereisum Gonium)
Price: 7 Coins
Lets Chunky become invisible by pressing on a Chunky Pad. Sometimes makes invisible things visible. Available since Crystal Caves.