The Consumer Product Safety Commission said Tuesday that the Monster Science Growing Spider kits include a marble-sized toy that can be ingested.
If this occurs, the toy could expand inside the child's body, perhaps leading to serious medical complications, the commission said.
The agency is aware of one incident in which a similar water-absorbing polymer ball was ingested and had to be surgically removed.
The Monster Science Growing Spider kits were sold nationwide from August 2011 to November 2011 and from August 2012 to November 2012.
The toys sold for between $3 and $8, the commission said.
Consumers were advised to take the toys away from children and contact Amazing! Toys for a full refund.
Consumers can call 877-798-9795 for information.