Does stunning an Aniimo help capture it?

Aim a pod and the capture UI shows the exact percentage, so you can see what a stun buys you. Any throw below 100% can still fail after the pod shakes, which is why the stun window matters: it is the moment the number is high enough to spend a pod on.

Stunning sits alongside the broader rule that weakening a wild Aniimo raises its capture rate. Damage, a lower HP bar and a depleted break gauge all push the odds up, and the harder an Aniimo is to catch, the more you need to soften it before a throw has a realistic chance. Lowering HP first also stops you wasting pods on evolved forms that would otherwise shrug them off. This holds during bloom events too.

Stun, break and Alphas

A full break goes further than a stun. Breaking an Aniimo opens a vulnerability window that lifts the capture rate above 90 percent, and to a guaranteed catch even with basic Aniipods. If you can push the break gauge all the way, do that before you throw.

Alpha Aniimo bosses, quest Alphas included, are the exception. You cannot capture one mid-fight, stunned or not. Defeating it gives you a chance to catch it, and that chance is low.

When you do not need to fight at all

Combat is not the only route. Alerting an Aniimo lowers its capture rate, so a creature you never disturb can be easier than one you have to stun. Throwing from behind gives a back attack bonus that greatly raises the chance, awake or asleep. A sleeping Aniimo is the easiest catch in the game, and can be taken with the cheapest pod. Traps set in the terrain and decoys like duckies help you set those catches up.

Save stuns for creatures that have already spotted you or that you need to beat down anyway.

Not settled: How far a break raises the odds is not settled. It is above 90 percent at minimum and may be a guaranteed catch, so check the percentage on screen before you throw.