Question: In my story, I want a creature to be immune to bullets, but giving it bulletproof skin seems too obvious. I want it so that you could shoot the creature a few times at its seemingly vital spots (the head, heart, etc.), but it won't die right away and can still escape or attack you. The best way to make sure it dies quickly is by draining most of its blood, which means you have to get close enough to cause a large wound with a bladed weapon.

Yes, I know you can just use a really big gun or explosives to achieve the same effect, but in this scenario, the options are limited to something relatively cheap, lightweight, and doesn't cause a lot of collateral damage. To give you some image, the creature is about as agile, as strong, and as big as a polar bear.

Preferably the reason it's immune to bullets is based on real animals, or at least something that could exist in the natural world.

Answer: 
Amorphism, if the creature has no vital organs but rather is composed of "full function" non-specialised cells that all do a bit of everything but require a certain critical mass to function as a whole. Then point damage like a bullet wound does little to no damage to the overall organism while cutting it up with a sword reduces individual sections below survival mass killing chunks of it off until the whole no longer has enough cells to grow back. Something like the [Oozes](https://www.d20pfsrd.com/bestiary/monster-listings/oozes) of Dungeons and Dragons or Calvin in [Life](https://en.wikipedia.org/wiki/Life_(2017_film)). Real world examples of amorphic life are the [Sponges](https://en.wikipedia.org/wiki/Sponge) that have mutable cell functions based on location rather than a fixed function for a given cell.
**FUR**

What about a massive stubborn fur, that is thick enough to absorb most of a bullets energy or/and deflect it from it's original path.

**HORNS**

The creature also could have horn like growths around its vital spots, which can deflect a bullet from the vital area when incoming on certain angels.

This still mean that a bullet may be deflected to a less vital area or if shot at the right angel (which might be difficult) still might hit a vital area. This makes it also very challenging to hunt such a creature.