Step 1: Analyzing the Green lizard's progress.
In each attempt, the Green lizard climbs 3 feet and slides 1 foot back. Thus, in each attempt, the net progress is 2 feet (3 feet up - 1 foot down).
After 4 attempts, the Green lizard will have climbed:
\[
4 \times 2 = 8 \, \text{feet}
\]
In the 5th attempt, it climbs 3 feet and reaches the top, for a total of 10 feet.
Step 2: Analyzing the Red lizard's progress.
In each attempt, the Red lizard climbs 4 feet and slides 2 feet back. Thus, in each attempt, the net progress is 2 feet (4 feet up - 2 feet down).
After 3 attempts, the Red lizard will have climbed:
\[
3 \times 2 = 6 \, \text{feet}
\]
In the 4th attempt, the Red lizard climbs 4 feet and reaches the top, for a total of 10 feet.
Step 3: Conclusion.
The Red lizard reaches the top in fewer attempts (4 attempts) compared to the Green lizard (5 attempts).
\[
\boxed{(C) \, \text{Red lizard}}
\]