Bulbagarden

Rolycoly.
Carkol.
Coalossal.
Gigantamax Coalossal.
Gulpin.

Unown?

this is uninspired
Sobble - rehash of Froakie
Inteleon - rehash of Greninja
Cubchoo - rehash of Teddiursa
Beartic - rehash of Ursaring
Lilligant - rehash of Bellossom
Purrloin - rehash of Glameow
Mightyena - rehash of Houndoom

Disappointing is highly subjective--I am quite disappointed with Inteleon but many really like it for example--so I'll focus on uninspired because I think that's a little less subjective. Goldeen, Seaking, Seel, Krabby, Magneton, Dugtrio, Sunflora, Luvdisc, Klink, Toucannon, Wooloo, and Carkoal are all Pokemon I'd say are more uninspred than Coalossal. At least Coalossal isn't just a cartoon version of something with a few tweeks to the design or a "just-add-two-more" evolution. Most monster-ish designs like Gigalith or Kommo-o tend to be a bit more inspired in my opinion compared to pure animals/plants because they don't have a distinct base in most cases.

Volbeat. Because I hate it with a passion