Thank you for this thread! I have some ideas that I would love to share! Here we go!
Yutai Yutai no Mi, Model: Red Kangaroo (Marsupial Marsupial Fruit, Model: Red Kangaroo)
The user can turn into a red kangaroo. The red kangaroo is the largest marsupial in general and the largest kangaroo in particular. In addition to superhuman strength, the user gains exceptional ability to jump but also can't stop hopping! Ideally a Longleg person would benefit from this fruit.
Yutai is short for yutairui, which is Japanese for marsupial.
https://translate.google.com/?hl=en&tab=wT#en/ja/marsupial
http://en.wikipedia.org/wiki/Red_kangaroo
Moai Moai no Mi (Moai Moai Fruit)
The user has the ability to summon and control Moai statues and shoot blue ring beams from their mouth (obligatory Gradius reference!). This fruit gives the user a permanent Moai face. The summoned Moai can be destroyed but are easily replaced. If the user is distracted or knocked out the Moai will be harmless statues. Hundreds of Moai can be summoned.
This is a Paramecia.
http://en.wikipedia.org/wiki/Moai
Sute Sute no Mi (Staple Staple Fruit)
The user becomes a Stapler Person who can shoot staples from their hands and feet or use their mouth as a stapler. The staples can be either normal or industrial strength. They can be used for combat or for practical reasons, like surgery or construction. The user is limited to 180 staples of any variety and must recharge either through downtime or consuming metal. This power takes a toll on the user's stamina.
This is a Paramecia.
Sute is short for sutepuru, which is Japanese for stapling.
https://translate.google.com/?hl=en&tab=wT#en/ja/stapling
http://en.wikipedia.org/wiki/Staple_(fastener)
Genshi Genshi no Mi (Atom Atom Fruit)
The user becomes an Atomic Person who has control over nuclear fusion and fission.
Fusion: The user has an internal fusion core. This means the user always has energy and doesn't need food, water or rest. The user can grant "fusion power" to objects and lifeforms alike. On the downside, fusion powered objects or lifeforms will also explode if too much force or pressure is applied to them.
Fission: The user can create explosions, similar to Pamu Pamu no Mi and Bomu Bomu no Mi. Unlike those fruits though, the fission aspect of the Genshi Genshi no Mi can be used to make lifeforms spontaneously combust. On the downside, this also applies to the user. Unlike the previously mentioned powers, the user would be permanently destroyed from self-destruction.
This power is exceptionally dangerous to everyone and everything. In fact it's also dangerous to the user, who must avoid self-destruction at all costs.
This is a Paramecia, though it could work as a Logia too if reworked a bit.
Genshi is Japanese for atom.
https://translate.google.com/?hl=en&tab=wT#en/ja/atom
http://en.wikipedia.org/wiki/Nuclear_fission
http://en.wikipedia.org/wiki/Nuclear_fusion
Uma Uma no Mi, Model: Paraceratherium (Horse Horse Fruit, Model: Paraceratherium)
The user can turn into a paraceratherium, an ancient hornless rhino. The paraceratherium was the largest land mammal to ever exist, the largest species of rhino and also the largest odd-toed ungulate. Rhinos are related to horses.
This is an Ancient Zoan.
http://en.wikipedia.org/wiki/Paraceratherium
Hito Hito no Mi, Model: Blemmyes (Human Human Fruit, Model: Blemmyes)
[Suggesting this as a major WTF power.]
The user can become a Blemmyes. This legendary tribe of humans had their faces on their chest. They were said to have super strength and were cannibals too. As a result, the user gains immense physical strength but also disturbing craving for flesh, including human flesh!
Like the Yami Yami no Mi, the Hito Hito no Mi, Model: Blemmyes is a unique fruit. Humans and humanoid species that consume this fruit won't have a hybrid form. Non-humanoid creatures that consume this fruit would obtain a humanoid form, albeit as a Blemmyes-esque creature. Oddly enough this Zoan can't be "eaten" by inanimate objects.
The biggest disadvantage of this fruit is that the user's intelligence decreases when they become a Blemmyes. When in normal form, the user is noticeably aggressive and temperamental.
This is a Mythical Carnivorous Zoan.
http://en.wikipedia.org/wiki/Headless_men