Iowa Code § 621.1: Bond for costs.

If a defendant, at any time before answering shall make and file an affidavit stating that the defendant has a good defense in whole or in part, the plaintiff, or party bringing the action or proceeding, if the plaintiff or party is a nonresident of this state, or a private or foreign corporation, before any other proceedings in the action, must file in the clerk’s office a bond with sureties to be approved by the clerk, in an amount to be fixed by the court, for the payment of all costs which may legally be adjudged against plaintiff.