Correct sentence:
Pumas hunt at night and can carry prey that weigh up to five times as much as they do.
Why this is better (easy steps):
- "Prey" can mean more than one animal, so we use the plural verb weigh (not weighs).
- Saying "weigh up to five times as much as they do" clearly compares the weight of the prey with the puma. The original phrase "than their weight" sounds awkward.
- Example to show "five times": if a puma weighs 30 kg, prey five times as heavy would weigh 150 kg (30 × 5 = 150).
Simple alternative: Pumas hunt at night and can carry animals that weigh five times as much as they do.