Kermit is very cute! Don't wet budgies look ridiculous?
It is hard to tell from the picture the length of Kermit's upper and lower beak. Since his upper beak is deformed, I would watch him to see if the length of the lower part of his beak is causing him any discomfort or difficulty. If so, you definitely should take him to an avian vet to get the problem addressed. Any beak trimming should be done by a vet or someone else very experienced in working with birds.
A quick google search on beak deformities says that there are a number of different causes for beak deformity. Some can be solved helped by the proper care, including diet and trimming. I highly suggest you take Kermit to an avian vet to get his beak looked at by an expert. If you don't have a regular avian vet near you and see an exotics vet normally, it might be worth a longer trip to see an avian vet or to have your vet consult with an expert. Universities with vet schools would also be a good source of expert advice on something like this if you are not getting answers. Because his beak health could affect the rest of Kermit's life, it is a good idea while he is young (am I correct in remembering he is young?) to address this and to learn proper care.
I am by no means an expert, just a good goggler and avid reader who dabbles in science. I hope this is helpful.