Not sure if Pain-69 wants size or strength, with regards to forearms..but anyway, lot of excellent suggestions offered. A few I might recommend that you may get more bang for your buck from;
Montague is describing the old style wrist roller, I believe. A very, very superior way to work the forearms, wrist and grip. Usually made from a short handled dowel , with an eye hook in the middle, where the rope is looped through. The other end of the rope will have a BB plate tired to it. Can do the exercise with hands facing down (usually way) or hands facing up. The longer the rope, the more intense the exercise. Some will stand on a bench, with a longer rope of course, to get max effort from the rolling action of the hands/grip. The burn will be unbelievable as will the pump. Prefer holding the arms straight out in front of the body. Some will keep the elbows to the side, having the forearms at a 90 degree angle ( another simple exercise is to grab the corner of a full size newspaper and begin wadding it up in the palm of the hand until forming a large ball. Than squeeze even more).
As Donny and Montague also mentioned, BB reverse curls (straight bar here..elbows locked to the sides) is a good forearm movement as well as a bicep builder. It will build forearm size.Though it may not improve the desired goose neck effect when flexing all that much.
For heavy strength, take a BB from a PR/stands/boxes, etc , using a false grip (thumb same side has the fingers) and just hold for 10 seconds. Build up to 20 seconds before adding more weight the following workouts. The surprise is, you do this with one hand at a time. Not the usual sissy two hand stuff. Can also do this with a heavier DB (watch the toes).
Try hanging from a chinning bar (start with a regular grip..advance to a false grip...something I learned from rock climbers, who depend more on their finger grip rather than thumbs and a over lapping grip..the men & women have amazing grip endurance and strength) with added weight for the 10 to 20 second max. Again, doing this one hand at a time.
For the pinching/squeeze grip, try gripping a overhead beam (anywhere from 2 to 4 inches) with both hand and do pullups. Add weight as you become stronger. Good Luck.