Answer:
A person
Step-by-step explanation:
I have heard this riddle multiple times, it is very well known and ( in my opinion ) very intriguing;
If we are considering the 4 legs in the morning, we can assume it to be a baby crawling on all 4's. 2 legs in the afternoon represents a more elderly person, a young child or adult on their 2 legs, and 3 in the night models an elderly person, using a walking stick as their " leg "
Answer; In other words, a person has 4 legs in the morning, 2 in the afternoon, and 3 at night
