What kind of fallacy is "practice makes perfect, but nobody is perfect therefore I do not need to practice" ?

There is some equivocation going on, along with a loose definition of "perfect."

Practice makes perfect...

"Perfect" here refers to the action/behavior being practiced, not the person.

but nobody is perfect...

Now "perfect" refers to the person as a whole (equivocation).

therefore I do not need to practice

This doesn't follow ( non sequitur ) due to a) the use of equivocation and b) the fact that nobody has achieved perfection doesn't mean they can't/won't. Consider:

(prior to 1952)

"Practice is needed to run a mile in under minutes, but nobody has ever done it, so practice is pointless if running a sub-four-minute mile is your goal."

non sequitur?

And a weird one too...why would others not being perfect imply one needn't practice?

Much of what leads to the "don't need to practise" conclusion is imprecise use of language ... aside from the equivocation with the understanding of "perfect" that Dr. Bo mentions.  If we assume that "practice makes perfect" means that enough of the right kind of practice leads to accomplishing something to a desired standard, then in "if ... then" form, the first premise becomes something like:

If ones does enough of the right kind of practice, then one can achieve the desired standard.

The "nobody is perfect" premise would become something like: "No one has reached the desired standard".

With these substitutions, the argument becomes:

If one does enough of the right kind of practice, then one can achieve the desired standard.

No one has achieved the desired standard.

Therefore ... it would seem that the logically valid conclusion from these premises is that no none has done enough of the right kind of practice.

Jumping to the conclusion that practice isn't needed doesn't follow logically from the premises given.

Having said that, I suspect that the "practice makes perfect" statement wasn't intended so much as a logical argument as it was presented as a catchy expression (what we might now call a "sound bite") to point out that certain skills (mental and physical) can be improved with practice.