Screamer
The Screamer is a rollercoaster featured in GTA IV at the Funland theme park in southern Broker.
The ride is not accessable by Niko but a vehicle wide enough to stay on the tracks (i.e. Comet), but not so long that it gets jammed round tight bends, can be used to drive along the track.
At the highest point, around the middle of the coaster track is a [[Flying Rats|pigeon]
Trivia
In the game manual of Grand Theft Auto IV there's a category for the Screamer and it says, "Too bad you can't ride the Screamer because what would be better than riding a 100 year-old rollercoaster made out of wood?"