Igglybuff in depth
Puchi plus Purin
The Japanese name is a straightforward contraction: ププリン (Pupurin) combines プチ (puchi, “small”) with プリン (Purin), which is what Jigglypuff is called in Japan. “Small Purin”, literally. English reaches the same place by another route — Igglybuff rhymes with both Jigglypuff and Wigglytuff, and carries buff, a pale, flexible leather. The French Toudoudou plays with tout doux and doudou, the stuffed toy a child won't let go of.
The design doesn't start from an animal. It starts from a balloon, because of its inflatable body and its official category, Balloon Pokémon, which it shares only with Qwilfish and Drifloon. There's also a powder puff in its shape and color, and a musical nursery toy of the kind that plays sounds to help a child fall asleep: hence the singing, and hence the Pokédex entries' insistence on how soft it is.
The day it stopped being Normal
It was pure Normal type until Generation V. Generation VI added the Fairy type without changing a single stat, completely reshaping its matchup chart: it gained an immunity to Dragon on top of the one it already had to Ghost, as well as resistances to Bug, Dark and Fighting. In exchange, it got two new weaknesses, Poison and Steel.
That same adjustment turned moves it already knew into same-type attacks, even though they had previously been Normal, including Sweet Kiss and Charm. None of this made it usable. Good typing on 15 Defense and 20 Special Defense is a well-built roof over a house with no walls.
Two pink babies from '99
It arrived with Gold and Silver, in the batch of baby forms that Generation II placed underneath creatures that already existed. The parallel case is Cleffa: the same idea, the same Fairy typing added later, the same friendship evolution and exactly the same 15 Speed — the two share the record for slowness among Fairy Pokémon.
The difference is in the distribution. Cleffa spreads its points more evenly; Igglybuff piles almost all of them into HP and leaves the rest at rock bottom. It's a design choice consistent with what it represents: a soft sack that takes the hit but doesn't give one back.
Its practical use is still the same as in 1999. You breed it, hatch it in two thousand-odd steps, teach it whichever egg moves you want, give it some affection and level it up once. From there, the team has a Jigglypuff, which isn't much cop either, but at least it survives one turn.