Capsule Kaiju (カプセル怪獣, Kapuseru kaijū?) are monsters, aliens or ultras that exist in a capsule most of the time, only to materialize when used by someone. They can understand commands of the user. They first appeared in Ultraseven and was used frequently by Dan to fight kaiju when he could not transform into Ultraseven.
- There were five capsules shown in Ultraseven, but only three were shown materialized as kaiju.
- Capsule Kaiju, are one of the several inspirations for the creation of the Pokemon Franchise.