Agent Sandra is and exchage agent from the Seal Agency. Her little brother, Harpy, is training to be an agent. Sandra is a bossy and snobby to Wallree, Wilson, and Wendy, but they are friends in times of need. Sandra and Harpy first appeared in Agent Wallree and the Danger Down Deep. Mayor Seal brought them to the Walrus Agency after he saw the Wallree, Wilson, and Wendy had failed their last mission. Chief Wendall gladly accepted them into the agency.
- "You're still in training, Harpy!"
- "I have better things to do than laze around with you blubber bags!"
- "Tusks are for idiots who can't use their flippers"
- "Don't influence Harpy with all of your shinanigans. I don't want him to turn out like SOMEpeople around here!"
- Sandra does not yet appear in the movies.
- After becoming orphans in Sealville, Mayor Seal became Sandra and Harpy's guardian.