The majority of Pokemon have another form to strive for. They evolve into something much stronger; even twice at times.
A Pokemon is said to be at its strongest when it is fully evolved. That rings true for the likes of Charmander and Magikarp. When they evolve completely, they reach their peak.
A large amount of fully-evolved Pokemon, however, are still considerably weak. In terms of total base stats, the weakest final evolutions should come as no surprise. They are all Bug-types.
Top 5 weakest fully evolved Pokemon
#5 - Beautifly
Beautifly has a base stat total of 395. Bug-type Pokemon tend to evolve a lot quicker than many other types. That appears to be more of a negative than it is positive. Beautifly's highest base stat is its Special Attack at 90. Next to that is Attack at 70.
#4 - Ledian
Ledian's base stat total is a lacklustre 390. It actually has a very good Special Defense stat at 110. Its Speed is a solid 85, too. Everything else is 55 or under. That is incredibly weak. It fails as a fighter and as a physical defender. Bug-type Pokemon really are the weakest type. It isn't an opinion; it is a fact.
#3 - Dustox
The base stat totals just keep lowering. Dustox comes in at 385. Like many other Bug-types, Special Defense is its best stat. 90 is where it lands in that category. Nothing else even comes close.
It is extremely fragile with low Defense and HP. Its Speed is a lowly 65. As Bug/Poison-type Pokemon, it just receives another weakness in the form of Psychic.
#2 - Kricketune
A lot of Pokemon fans love Kricketune. It has received some awesome trading cards and has a cool mustache. It has a surprisingly low total base stat of 384, though. Attack and HP are decent compared to others on the list, but nothing else reaches past 65. Kricketune is nothing more than a cosmetic favorite.
#1 - Shedinja
With weakness being determined by base stats, Shedinja takes the cake. Its base stat total is 236.
Now, Shedinja is a pretty unique and fairly useful Pokemon. It has a decent Attack stat, but everything else is awful, including its 1 HP stat. Shedinja has the ability Wonder Guard, however.
That makes it immune to every damaging attack except supereffective hits. That can come in pretty handy, but one supereffective sneeze in its direction and Shedinja is done for.