There are several bodyweight exercises that can help you build bigger and stronger forearms. Here are a few effective exercises:

1. Pull-ups: This exercise primarily targets your back and biceps, but it also engages your forearms. As you pull yourself up, focus on gripping the bar tightly and squeezing your forearms.

2. Push-ups: While push-ups primarily target your chest, shoulders, and triceps, they also engage your forearms. To increase the forearm engagement, try doing push-ups on your fists instead of your palms.

3. Handstands: Handstands require significant forearm strength to support your bodyweight. Start by practicing against a wall and gradually work towards freestanding handstands. You can also try variations like handstand push-ups to further challenge your forearms.

4. Plank variations: Planks are excellent for building core strength, but they also engage your forearms. To increase the forearm engagement, try performing planks on your fists or with your forearms on the ground instead of your palms.

5. Farmer’s walks: This exercise involves walking while holding heavy objects in each hand. It targets your forearms, grip strength, and overall upper body strength. You can use dumbbells, kettlebells, or even heavy water jugs for this exercise.

6. Wrist curls: Sit on a bench or chair with your forearm resting on your thigh, palm facing up. Hold a weight (dumbbell or any other weighted object) in your hand and slowly curl your wrist upward, then lower it back down. Repeat for several reps and switch to the other hand.

Remember to gradually increase the intensity and resistance as your forearms get stronger. Additionally, proper nutrition and sufficient rest are essential for muscle growth and recovery.