Judges 14:14 And he said unto them, Out of the eater came forth meat, and out of the strong came forth sweetness. And they could not in three days expound the riddle.
This riddle was born of Samson’s experience with a lion in Timnath.
Judges 14:5 Then went Samson down, and his father and his mother, to Timnath, and came to the vineyards of Timnath: and, behold, a young lion roared against him. 6 And the Spirit of the LORD came mightily upon him, and he rent him as he would have rent a kid, and he had nothing in his hand: but he told not his father or his mother what he had done. 7 And he went down, and talked with the woman; and she pleased Samson well. 8 And after a time he returned to take her, and he turned aside to see the carcase of the lion: and, behold, there was a swarm of bees and honey in the carcase of the lion. 9 And he took thereof in his hands, and went on eating, and came to his father and mother, and he gave them, and they did eat: but he told not them that he had taken the honey out of the carcase of the lion.
So the answer was, as you suggest, a lion.
I hope you find this helpful.