Togepi in depth
A spike with a diminutive
The Japanese name, トゲピー, combines 棘 (toge, spike or thorn) with the ending -pī, the affectionate suffix used with children's names. Spike plus diminutive: the small creature with points. English didn't bother changing it, and neither did Spanish, which is unusual for a generation in which many names were rewritten from top to bottom. The official category translates the same idea by another route — Spike Ball Pokémon.
The design follows the same literal direction. It's an egg with legs, and the interesting detail is that the shell doesn't break: it stays with the Pokémon, with the spikes drawn on the shell instead of sticking out. No Pokédex entry describes what's underneath. When it evolves, the shell simply disappears from the design.
The day it stopped being Normal
Until Generation V it was a Normal type. Generation VI reclassified it as Fairy alongside the other obvious candidates, and the change wasn't cosmetic. As a Normal type it had one weakness, Fighting, and one immunity, Ghost. As a Fairy type it gets immunity to Dragon, resistance to Fighting, Bug and Dark, and two new weaknesses, Poison and Steel. On a creature with 65 Defense and 65 Special Defense, trading one weakness for two matters less than gaining three resistances.
What really changed was the same-type attack bonus. Moonblast, which it learns at level 43, now gets STAB, just like Fairy Wind and Draining Kiss. Before that, Togepi's Fairy repertoire was a repertoire without support. Cleffa took exactly the same path in the same update, and for the same reasons.
The abilities are a loan
Togepi's three abilities are designed with the end of the line in mind, not with Togepi itself. Hustle, which raises Attack while lowering accuracy, is a joke about 20 Attack. Super Luck, the hidden ability, multiplies the critical-hit rate of an attacker that never becomes an attacker. Serene Grace is what has kept Togekiss relevant in competitive play for generations, because doubling the chance of a secondary effect on a move that makes the opponent flinch turns every one of the opponent's turns into a coin toss; on Togepi, the same ability applies to Psychic at level 34 and little else.
It's worth looking at the order in which the moves arrive, because it explains why nobody stays at this stage. Tackle at 1, Fairy Wind at 6, Draining Kiss at 11 and Calm Mind at 18 cover the early stages without a single hit above 50 power. Baby-Doll Eyes, at 25, lowers the opponent's Attack and is probably the most useful thing it does, because it partly makes up for the 35 HP. Psychic arrives at 34 and Moonblast at 43 — by then, with friendship at 160 or higher, any trainer who has treated the little thing well has had a Togetic for some time, or a Togekiss outright.
The egg on request
There's a pattern that has repeated since 1999: the games don't let you find it, they give it to you. Elm's aide in Goldenrod City, the man in the Water Labyrinth, Cynthia in Eterna City, the old woman in Lavaridge Town. Always a character handing over a sealed egg, always for nothing in return, and always with hatching as part of the gift. The mechanic fits what the Pokédex entries say — a Pokémon that stores other people's goodwill and gives it back — and, as a bonus, teaches the player how eggs work without needing a Day-Care worker.
The anime did the same thing from outside the fiction: the egg appears before the creature, and the Togepi that hatches from it ends up with Misty because she was the first thing it saw when it opened.