Bill is correct; a turkey baster. Another alternative is a truck-size radiator fluid tester (I found one at an auction which is identical to a turkey baster, except it is made out of glass).
The battery bulb filler beats the turkey baster anyday as the rubber on the TB cannot hold up to most automotive fluids. The BFB is same principle with a bigger bulb and thicker rubber which makes it easier when sucking up thicker fluids such as gear oil etc.
A metal syringe type suction gun can be found at your local AutoZone, NAPA and so on for about $8.
Ray