How does shuckle appear in Pokemon FireRed?
Shuckle is not available in Firered you will need Emerald to trade you one you will need to use Rock Smash in the secret part of the Safari Zone to find it.
Shuckle is catchable but only in Emerald version after beating the elite four and champion. In the Safari Zone a special area is available for the capture of Johto pokemon these include: Teddiursa, Mareep, Gligar, Houndour, and Shuckle. Shuckle however does not appear in the grass instead you must find it by using Rock Smash on the small rocks within the area.
Pokemon Emerald takes place in the Hoenn region, whilst Pokemon Firered takes place in the Kanto region. Emerald was a third version of Ruby and Sapphire, when Firered and Leafgreen were remakes of the original Red and Blue. The most major difference is what Pokemon appear, the locations, and the trainers.