The Astro Pets - Large Growing Pets in a Rocket is a science-themed, water-activated toy designed for children aged 5 and up. It consists of a, usually, red, white, and blue rocket-shaped capsule that houses a squishy, surprise animal astronaut character. 

Key Features and Description:

• Growing Mechanism: When submerged in water, the outer rocket capsule dissolves over 24 to 48 hours"launching" the astronaut pet inside.
• Growth Process: Once the rocket breaks apart, the squishy pet continues to expand, often reaching full size within 78 hours.
• Characters: The pets are typically bright, assorted astronaut-themed animals, such as a pink kitty, brown dog, or tan fox.
• Reusable/Repeatable: If the pet is removed from water and allowed to dry, it will shrink back down and can be regrown, allowing for multiple uses.
• Size: The rocket capsules are generally around 3.5 inches in height before growing.
• Educational Aspect: The toy demonstrates basic polymer science and osmosis. 

How to Use:

1. Place the entire rocket capsule into a container of water.
2. Wait for the outer shell to dissolve (24–48 hours).
3. Once the pet appears, it can be moved to a new, larger container of water to continue growing. 

Note: The toys are sold individually, and the style is often random.