- Clamperl, Huntail, and Gorebyss. Brings nothing to the table without evolving. Belongs to a common type.
- Alomomola. Misspells its name as "Alolamola" constantly. Suffers from the same Water-type fatigue as above.
- Stantler. Always thinks of Sawsbuck.
- Mothim. Competes with Venomoth, Dustox, and Masquerain for memory.
- Swadloon (and Sewaddle and Leavanny to a lesser extent). Likes its evolution line, though.
Well, many people probably remember Stantler when they think about "forgettable" so it's probably not forgettable at all :). Truly forgettable Pokémon would be those that are hard to remember they exist without looking at the Pokédex and seeing them.
Remembers Cherrim/Cherubi, Bergmite/Avalugg, and Klink/Klang/Klinklang fairly well due to past threads like this. Inked Avalugg further into memory by specifically seeking them out for a Sword Ice monotype. Fared well with Ice Body, Leftovers, Recover, Iron Defense, and Body Press.