How do you get guillotine in FireRed?

In Pokémon FireRed, you cannot obtain the move Guillotine as a TM or HM. Instead, it is a move that can only be learned by certain Pokémon, specifically by some species of the Generation I Pokémon, like Tentacruel and certain others through leveling up. To acquire it, you'll need to level up these specific Pokémon to the appropriate level where they can learn the move. Remember that Guillotine is a one-hit knockout move with low accuracy, so use it wisely!