local Remote = game.ReplicatedStorage.Remotes.GigantificationRemotes.GigantificationFire
Remote.OnServerEvent:Connect(function(Player,Mouse)
local player = game.Players.LocalPlayer
local character = player.Character
while true do
wait(0.25)
character.Torso.Size = character.Torso.Size + 1,1,1
wait(4) break
end
end)
getting an error at "local character"

2 comments
Line 5 should be Player:WaitForChild("Character"). It will actually wait until it exists.
No, Character is a property of the Player instance and waiting for a child named "Character" will not work. The way the fifth line works is that if Player.Character is nil, Player.CharacterAdded:Wait() makes the script yield until the CharacterAdded event fires and then returns the character as an instance (as CharacterAdded passes a character argument when fired)