It is wooden, has stone carvings of ape heads on it and is colored brown.
The bongos are exclusive to Ape Mountain. To activate them, you must first toggle the winch icon on. You will know if is activated because it will have two sticks in a cross shape on it if it isn't. When toggled on, drop a Pygmy on it and it will become possessed. Tap the the sky or the bongos repeatedly and they will drum the bongos (as if you wanted the Pygmies to dance) and the giant ape will be summoned, but this will only work if the torches are lit and the Pygmy in the altar is winched until the skulls on the altar have a yellow glow from their eyes by using the winch. If the Giant Ape is present when the Pygmy in the altar rips apart, he will get angry and will squash the Possesed Pygmies on the bongos and winch. Tapping the bongos also makes the giant ape dance.