Just helping a donkey entertain their kid!

pedcycler.lua

-- Here we list our ped models we want to cycle through.
local pedCycle = {
    "s_m_y_fireman_01",
    "s_m_y_hwaycop_01",
    "s_m_y_marine_03",
    "s_m_y_swat_01",
    "s_m_m_fibsec_01",
     "s_m_m_paramedic_01",
    "s_f_y_scrubs_01",
    "g_m_m_chicold_01",
}

local currentPed = 0 -- This will hold our place in the cycle.
-- It is initialized at 0 so the first time we increment it, it will go to the first element in the table.

local function LoadModel(model)

    -- First we check if it's even worth attempting
    if not IsModelValid(model) then
        print('Model ' .. model .. ' is invalid')
        return false
    end

    -- Then we make the initial request
    RequestModel(model)

    -- Let's store when we started waiting, so we know when it has timed out
    local begin = GetGameTimer()

    while not HasModelLoaded(model) do

        if GetGameTimer() > begin + 1000 then -- That is, if it has been over a second since we started loading
            print('Failed to load model ' .. model)
            return false -- Bail out, and report failure
        end

        -- Or keep waiting a little longer
        Citizen.Wait(0)
    end

     -- If we got here, that means it loaded!
    return true
end

local function VehicleIAmIn()
    if IsPedInAnyVehicle(PlayerPedId(), false) then -- Because if we're not in a car, we don't care, right?
        local vehicle = GetVehiclePedIsIn(PlayerPedId(), false) -- Set the vehicle

        -- Just in case we're not the driver, we'll cycle through all the seats to find the one we're in
        for seat = -1, GetVehicleNumberOfPassengers(vehicle) do
            if GetPedInVehicleSeat(vehicle, seat) == PlayerPedId() then
                return vehicle, seat
            end
        end
        -- If we're somehow *not* in any of the seats, it will fall off the end of the function, returning nothing.
        -- This is the same as not being in a vehicle at all.
    end
end

local function SwapModel(model)
        -- Swap out the player model!
        SetPlayerModel(PlayerId(), model)

        -- To avoid leaving lots of ped models loaded when we don't really need them, we mark it as "GTAV can forget about it when it doesn't use it anymore"
        SetModelAsNoLongerNeeded(model)

        -- Most peds have some props they can use, like the firemen have helmets and smoke masks, the cops have mirrored glasses, etc
        SetPedRandomProps(PlayerPedId())

        -- Components are the bits and pieces a ped is built from. This can vary just about anything, like skin color and uniform details.
        SetPedRandomComponentVariation(PlayerPedId(), 0)
end

local function NextPedPlease()
    -- First we increment the place in the cycle
    currentPed += 1
    -- Then we check if it's out of bounds, and wrap around if it is.
    if currentPed > #pedCycle then
        currentPed = 1
    end

    -- Now we have the index we want, and can look up the model
    local model = pedCycle[currentPed]

    -- To become this ped, we'll have to load the model.
    if not LoadModel(model) then return end -- If it doesn't report success, then it's meaningless to continue the process.

    -- Let's store the position of the camera, as switching player model resets the camera to be right behind the player ped.
    local camHeading = GetGameplayCamRelativeHeading()
    local camPitch = GetGameplayCamRelativePitch()

    -- Figure out what vehicle and seat we're in, if any
    local vehicle, seat = VehicleIAmIn()

    -- Swap out the model
    SwapModel(model)

    if vehicle then -- That is, we were in a vehicle before
        SetPedIntoVehicle(PlayerPedId(), vehicle, seat)
    end

    -- After the ped is loaded and set up, we put the camera back where it was.
    -- This happens in a single frame, so the user won't see the camera move unless they're pressed up against a wall, or sat in a vehicle.
    SetGameplayCamRelativeHeading(camHeading)
    SetGameplayCamRelativePitch(camPitch, 1.0)
end

Citizen.CreateThread(function()
    while true do -- Infinite loop.

        -- An infinite loop will stall the client unless we yield the thread every now and then.
        -- We should yield it as short as possible to not miss any keypresses.
        Citizen.Wait(0)

        -- If the key we want is pressed...
        if IsControlJustPressed(1, 174) then -- Controls are listed at https://docs.fivem.net/docs/game-references/controls/#controls -- 174 is INPUT_CELLPHONE_LEFT, usually bound to Left arrow and DPad Left
            NextPedPlease()
        end
    end
end)

EEEEEEAAAAAAAAWWWWWWWW this is one happy donkey !