Why is my apple so spiky?

Go Won had this caption for her fourth teaser photo. Spiky? Since when apple is spiky? I randomly looked it up and it turns out there is a 'spiky apple'. Oh my. 

I had a few candidates regarding this 'spiky apple'. The first one is sugar-apple or sweetsop or custard apple. It's also well-known as atemoya or 'pineapple sugar apple', a hybrid between the sugar-apple and the cherimoya, is popular in Taiwan. As its name suggests, it tastes like pineapple.

Cherimoya looks similar to sugar-apple, but it's called custard apple thanks to the creamy texture of its flesh. It is grown in tropical regions throughout the world. Mark Twain called the cherimoya "the most delicious fruit known to men".

The snake fruit, locally known as salak is a species of palm tree native to Java and Sumatra, Indonesia, also naturalized in Bali, Lombok, Timor, Malaysia, Maluku and Sulawesi. It's not a type of apple but the word snake sort of reminds me of serpent whom deceived Adam and Eve in the Garden of Eden. 

Bael (Aegle marmelos) is someti