Like most other arm balances, Mayurasana (Peacock Pose) appears to require exceptional strength. What is actually needed, though, is patient, progressive work to develop a more intimate relationship with gravity.
To begin doing this, you'll need to create a sturdy foundation for the pose that uses your hands, your forearms, and your belly. Think of your hands as your feet, and your forearms as your legs. Once you set up a solid base, you'll need to press your elbows deep into your belly, which might initially make you flinch and tighten your gut. It will feel counterintuitive to soften your belly around your elbows and dig your elbows into that flesh, but that's exactly what you'll need to do in order to complete the pose. Once you're able to do this, you'll find a strong set of deep abdominal muscles underneath the often-overused rectus abdominus (aka your washboard abs); these will keep you stable. To finish the framework of Mayurasana, you'll also need open shoulders and wrists.
As you master this pose, you will ultimately gain tranquility in the midst of discomfort, allowing you to move beyond your edge and trust that an inner elasticity will support you if you surrender.