Final answer:
A complex virus possesses characteristics of both a polyhedral and helical virus. They have additional structures such as protein tails or a complex outer wall.
Step-by-step explanation:
A complex virus possesses characteristics of both a polyhedral and helical virus. Complex viruses have a capsid that is neither purely helical nor purely icosahedral, and may have additional structures such as protein tails or a complex outer wall.
Phage viruses are examples of complex-shaped viruses, with an icosahedral head attached to a helical tail. The tail may have tail fibers that aid in virus attachment to host cells.