HM05 Flash in FireRed.

Flash. An HM can be taught to any number of Pokemon and the move cannot be forgotten without the Move Deleter. 155 species in Pokemon FireRed can learn it.

Bulbasaur, Ivysaur, Venusaur, Butterfree, Pikachu, Raichu, Clefairy, Clefable, Jigglypuff, Wigglytuff, Oddish, Gloom, Vileplume, Paras, Parasect, Venonat, Venomoth, Meowth, Persian, Psyduck, Golduck, Abra, Kadabra, Alakazam, Bellsprout, Weepinbell, Victreebel, Slowpoke, Slowbro, Magnemite, Magneton, Drowzee, Hypno, Voltorb, Electrode, Exeggcute, Exeggutor, Koffing, Weezing, Chansey, Tangela, Staryu, Starmie, Mr. Mime, Jynx, Electabuzz, Jolteon, Porygon, Zapdos, Mewtwo, Mew, Chikorita, Bayleef, Meganium, Hoothoot, Noctowl, Ledyba, Ledian, Spinarak, Ariados, Chinchou, Lanturn, Pichu, Cleffa, Igglybuff, Togepi, Togetic, Natu, Xatu, Mareep, Flaaffy, Ampharos, Bellossom, Hoppip, Skiploom, Jumpluff, Sunkern, Sunflora, Yanma, Wooper, Quagsire, Espeon, Umbreon, Slowking, Misdreavus, Girafarig, Shuckle, Porygon2, Stantler, Smoochum, Elekid, Blissey, Raikou, Entei, Ho-Oh, Celebi, Treecko, Grovyle, Sceptile, Beautifly, Dustox, Lotad, Lombre, Ludicolo, Seedot, Nuzleaf, Shiftry, Ralts, Kirlia, Gardevoir, Surskit, Masquerain, Shroomish, Breloom, Nincada, Ninjask, Shedinja, Skitty, Delcatty, Sableye, Meditite, Medicham, Electrike, Manectric, Plusle, Minun, Volbeat, Illumise, Roselia, Spoink, Grumpig, Spinda, Cacnea, Cacturne, Lunatone, Solrock, Baltoy, Claydol, Castform, Kecleon, Shuppet, Banette, Duskull, Dusclops, Tropius, Chimecho, Absol, Snorunt, Glalie, Metang, Metagross, Latias, Latios, Jirachi, Deoxys Normal