Answer: oobleck is made with corn starch and water. you can play with it like a bowl of soft glue but when you put force on it, it becomes solid.
Explanation: When you apply pressure to oobleck, it works the opposite of the previous examples: The liquid becomes more viscous, not less. At the places you apply force, the cornstarch particles get mashed together, trapping water molecules between them, and oobleck temporarily turns into a semi-solid material.
Oobleck is a suspension of cornstarch and water that can behave like a solid or a liquid depending on how much pressure you apply. Try to grab some in your hand, and it will form a solid ball in your palm until you release the pressure. Then, it will flow out between your fingers.