It looks trashy but this script makes an image GUI appear, then disappear.
while true do
--GUI starts
script.Parent.Transparency = 1
script.Parent.ImageTransparency = 1
script.Parent.BackgroundTransparency = 1
wait(4)
script.Parent.Transparency = 0.95
script.Parent.ImageTransparency = 0.95
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.9
script.Parent.ImageTransparency = 0.9
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.85
script.Parent.ImageTransparency = 0.85
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.8
script.Parent.ImageTransparency = 0.8
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.75
script.Parent.ImageTransparency = 0.75
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.7
script.Parent.ImageTransparency = 0.7
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.65
script.Parent.ImageTransparency = 0.65
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.6
script.Parent.ImageTransparency = 0.6
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.55
script.Parent.ImageTransparency = 0.55
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.5
script.Parent.ImageTransparency = 0.5
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.45
script.Parent.ImageTransparency = 0.45
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.4
script.Parent.ImageTransparency = 0.4
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.35
script.Parent.ImageTransparency = 0.35
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.3
script.Parent.ImageTransparency = 0.3
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.25
script.Parent.ImageTransparency = 0.25
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.2
script.Parent.ImageTransparency = 0.2
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.15
script.Parent.ImageTransparency = 0.15
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.1
script.Parent.ImageTransparency = 0.1
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.05
script.Parent.ImageTransparency = 0.05
script.Parent.BackgroundTransparency = 1
--Image is at 0 transparency
script.Parent.Transparency = 0
script.Parent.BackgroundTransparency = 0
script.Parent.BackgroundTransparency = 1
wait(6) --how long the image will appear [you can change this value]
script.Parent.Transparency = 0.05
script.Parent.ImageTransparency = 0.05
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.1
script.Parent.ImageTransparency = 0.1
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.15
script.Parent.ImageTransparency = 0.15
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.2
script.Parent.ImageTransparency = 0.2
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.25
script.Parent.ImageTransparency = 0.25
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.3
script.Parent.ImageTransparency = 0.3
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.35
script.Parent.ImageTransparency = 0.35
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.4
script.Parent.ImageTransparency = 0.4
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.45
script.Parent.ImageTransparency = 0.45
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.5
script.Parent.ImageTransparency = 0.5
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.55
script.Parent.ImageTransparency = 0.55
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.6
script.Parent.ImageTransparency = 0.6
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.65
script.Parent.ImageTransparency = 0.65
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.7
script.Parent.ImageTransparency = 0.7
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.75
script.Parent.ImageTransparency = 0.75
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.8
script.Parent.ImageTransparency = 0.8
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.85
script.Parent.ImageTransparency = 0.85
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.9
script.Parent.ImageTransparency = 0.9
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 0.95
script.Parent.ImageTransparency = 0.95
script.Parent.BackgroundTransparency = 1
wait(0.1)
script.Parent.Transparency = 1
script.Parent.ImageTransparency = 1
script.Parent.BackgroundTransparency = 1
wait(0.1)
--Image dissapears, intro completed.
script.Parent:remove()
end

2 comments
Welp, this works. Accepted answer.
Oh god, just use loops