Top 10 Worst One Piece Devil Fruits

Did we forget that Sengoku's fruit is the Human-Human Fruit?

This Devil Fruit allows you to turn into a human.
Very good if you aren't human, but not so good if you are human.
If you're human and eat this fruit, you lose the ability to swim and gain nothing.

That fruit can only be for animals

This fruit sucks!

This fruit lets you turn into 7 bouncy balls. Sounds great, until you realize that it is extremely weak to a sword swing and each ball can be cut in half easily. Not so great, considering every pirate ever seems to have a sword.

This Devil Fruit would be great for a small creature. If you ate this as a caterpillar or something, it would be a severe upgrade.

But as a human, getting the ability to turn into a hornet is very, very not useful, and will probably get you killed in combat situations.

This Devil Fruit allows you to create drawings that come to life. Sounds cool in theory, until you realize none of the drawings are very strong.

If you drew a big, bad, scary dragon, it would hit about as hard as a wet noodle slapping you in the face.

This Devil Fruit will revive you when you die. Sounds cool in theory, and it technically makes you immortal, but it isn't very good in combat, and overall is just kind of useless, dare I say.

Now, apparently Brook, the user of the Revive Revive Fruit, was able to use an ability called "Soul Solid" which lets him create Ice, but currently it isn't known if this is due to his devil fruit or a hidden ability.

This is useful?!

This one might not count, since it's artificial, and thus, weaker, but I thought I would put it here anyways.
SMILEs are Devil Fruits created in a lab. SMILEs allow the user to turn certain parts of their body into animal limbs, and not just arms into arms.

For example, I couldn't turn into a full Goat, but if I ate this fruit I could turn my hand into a goat horn.
Yes. I could turn my hand into a goat horn. And my leg into a goat's head. Etc. You get the idea.