There are weak Pokemon, but there is one that is a lot similar to another species of Pokemon. This Pokemon is known as Metapod. Metapod is a bug type Pokemon and isn’t very popular to even use when you first start your Pokemon journey. Metapod is similar to, probably equivalent to Kakuna. Kakuna is a bug type Pokemon who is just about the exact some Pokemon as Metapod, but slightly different. Metapod’s only attack it can get is known as Harden. Harden is an attack in which the Pokemon raises it’s own defense stat. Now this attack is completely useless if you don’t have any other attack that can be used. This will make it harder to defeat Metapod, but using Harden too many times can leave to it running out of power points, which are used to keep number of how many times you can use an attack. When these power points run out the Pokemon will have to use Struggle, Struggle is a fairly weak attack that will make the Pokemon that is out of power points attack, but it will lose health points, or HP, in the process by getting hit by recoil.
Running out of power points isn’t the only way to use Struggle, if the opponent trick the Pokemon by using Encore or an attack of that nature, and Disable, this will make it so the Pokemon can’t attack at all, resorting in it using Struggle. What does Metapod have in common with Kakuna anyway aside from having the same basic structure and body? Well Metapod’s pre-evolved form, Caterpie can get String Shot and Tackle, when it evolves into Metapod it will also know Tackle and String Shot. It will learn Harden as a Metapod. While Kakuna’s pre-evolved form, Weedle, can get String Shot and Poision Sting. It will evolve into Kakuna and will learn the attack known as Harden.
The only difference between these two is Metapod can get Tackle and Kakuna can get Poison Sting. Metapod is probably the strongest out of the two because Tackle does more damage than Poison Sting, but if Poison Sting poisons the Pokemon, Metapod and Kakuna have equal power.