Piggy Banks can contain Cash, Power Coins and Flip Coins. Each Piggy Bank type guarantees different item types and rarities, as well as a number of other random items. You can see these guarantees by tapping on a Piggy Bank.
Below you will find the odds of finding each item in different Piggy Banks (per draw):
PINK PIGGY BANK
Power Coins
Common 		1 in 2.56
Uncommon		1 in	5.13	
Rare			1 in 25.64
Epic			1 in 102.57
Flip Coins
Common 		1 in 5.13
Uncommon		1 in 20.51
Rare			1 in 341.91
Epic			1 in 8,547.83
Legendary		1 in 51,287
BRONZE PIGGY BANK & SAPPHIRE PIGGY BANK
Power Coins
Common 		1 in 4.1
Uncommon		1 in	6.84	
Rare			1 in 68.38
Epic			1 in 683.83
Flip Coins
Common 		1 in 2.05
Uncommon		1 in 10.26
Rare			1 in 205.15
Epic			1 in 5,128.70
Legendary		1 in 25,643.50
SILVER PIGGY BANK & EMERALD PIGGY BANK
Power Coins
Common 		1 in 4.74
Uncommon		1 in	6.33	
Rare			1 in 47.44
Epic			1 in 316.29
Flip Coins
Common 		1 in 2.71
Uncommon		1 in 4.74
Rare			1 in 47.44
Epic			1 in 632.59
Legendary		1 in 2,497.05
GOLD PIGGY BANK & RUBY PIGGY BANK & SILVER PIGGY BANK (SHOP)
Power Coins
Common 		1 in 8.90 
Uncommon		1 in	9.89	
Rare			1 in 44.50
Epic			1 in 222.50
Flip Coins
Common 		1 in 2.97
Uncommon		1 in 2.97
Rare			1 in 14.83
Epic			1 in 98.89
Legendary		1 in 296.67
DIAMOND PIGGY BANK & GOLD PIGGY BANK (SHOP)
Power Coins
Common 		1 in 18.42
Uncommon		1 in	15.35	
Rare			1 in 46.05
Epic			1 in 184.20
Flip Coins
Common 		1 in 4.61
Uncommon		1 in 2.30
Rare			1 in 6.58
Epic			1 in 30.70
Legendary		1 in 76.75
LEGENDARY PIGGY BANK & DIAMOND PIGGY BANK (SHOP)
Power Coins
Common 		1 in 24.83 
Uncommon		1 in	16.55	
Rare			1 in 49.65
Epic			1 in 99.30
Flip Coins
Common 		1 in 6.62
Uncommon		1 in 2.84
Rare			1 in 5.52
Epic			1 in 8.28
Legendary		1 in 16.55
LEGENDARY PIGGY BANK (SHOP)
Power Coins
Common 		1 in 43.85
Uncommon		1 in	29.23	
Rare			1 in 29.23
Epic			1 in 43.85
Flip Coins
Common 		1 in 8.77
Uncommon		1 in 2.92
Rare			1 in 4.39
Epic			1 in 8.77
Legendary		1 in 11.69