Granbull in depth
Grand plus bulldog
The name is one of the most direct constructions of the second generation. It is formed from the French grand, meaning large, joined to bulldog, and the Japanese グランブル is exactly the same compound with no changes. The breed is copied without disguise: the undershot lower jaw, the fangs showing outside the lip, the hanging skin, the wrinkled face. All of these are real bulldog traits taken to extremes.
What the design does with them is turn them on their head. An English Bulldog has a reputation as a fighting dog because of its history and as a calm dog because of its present-day temperament, and Granbull keeps both sides at once: the Pokédex repeats that its jaw has overwhelming strength and that, because it does not like fighting, it rarely gets the chance to prove it. Its Hidden Ability is Rattled. That is no accident.
The day it stopped being Normal
Until Generation V, it was an ordinary Normal type, with nothing to distinguish it from any other run-of-the-mill physical attacker. Generation VI changed it into a Fairy type, and the change reshaped its entire resistance profile: it gained immunity to Dragon and resistance to Fighting, Bug and Dark, lost the Ghost immunity it had by default, and picked up weaknesses to Poison and Steel.
There is a curious remnant of that former life. It still learns Outrage at level 1, a Dragon-type move with 120 power, on a Pokémon whose own type is immune to Dragon attacks. It is one of the few Fairies to carry one, and it is practically useful for nothing beyond reminding you where it came from.
Twenty levels without a move of its own
The level-up movepool is the species' real problem in a normal playthrough. It evolves at 23 and does not learn a single Fairy-type attack until Play Rough, which arrives at level 43. In between, it only has Charm, which is a status move. Twenty whole levels spent attacking with things that are not its own type.
What is available to fill the gap comes from earlier or from elsewhere. The three elemental fangs — Thunder Fang, Ice Fang and Fire Fang — are already available at level 1, each with 65 power, and provide decent coverage throughout the first half of the game. Bite comes at 7, Headbutt at 19 and Last Resort at 35, with 140 power and the condition that it must be the last move with PP remaining. Crunch does not appear until 59, by which point the game has been over for a long time.
The TM list broadens things considerably: Earthquake, Stone Edge, Close Combat, Focus Punch, the three elemental punches, Bulk Up to raise Attack and Defense at the same time, Encore and Taunt for disruption. With 120 Attack, almost anything physical you teach it hits hard.
What it is missing
The comparison with the rest of the physical Fairies is where you see the ceiling. It has plenty of raw Attack and lacks everything else: 45 Speed, 60 Special Defense and no recovery option other than putting itself to sleep with Rest. Every turn it survives, it survives through Intimidate and lowering the opposing Attack, and against a special attacker that plan does not exist.
It yields 2 Effort Points in Attack when defeated, and its base experience is 158.