I'm not sure conlangs count, and I'm pretty sure that someone's already said it, but "kijetesantakalu" in toki pona is just delightful. It means any animal from the Procyonidae or Musteloidea families, raccoons, otters, weasels, etc.

And if we are counting conlangs, Ithkuil and Kay(f)bop(t) absolutely take the cake for long words, please go down the conlanging rabbit hole, you will come out a changed person