"[Jyoti] made a nice salad burger for me and I was eating, and I put it on the plate and suddenly I look on the plate and there's something in it," he said.
"When I see that moving on my plate, I cannot describe how I feel, and I don't know how I'm going to eat food again. I will, I need to, but it's a concern at the moment."
He added: "If I'd eaten that salad with a fork and knife I could have cut into it and just eaten it.
"I think [eating] things like that alive, it's not good for your health, anyone could get sick, once you eat it, I don't know how to describe it, but it's dangerous in my mind."
The couple, who'd been Countdown customers for 20 years, took the bag of Krispkut Italian Style salad mix back to the store, and the plate with the caterpillar on it, and complained to the duty manager.
"She said, 'Yes, it is disgusting, it can't be like this', and she made all the notes so she can contact the head office," Mr Rahal said.
He received a follow-up phone call this morning, but said he was disappointed the man he spoke to said it could be a week before someone in head office got in touch.
"I'm not satisfied with that answer, that if they haven't contacted me within one week I should ring them again. Why should I ring them again? They should contact me as soon as possible."
The experience left Mr Rahal worried about what he could eat on his already limited diet.
"Now I think... I can't eat salad anymore, it's just in my brain," he said.
"My wife is concerned, she said to me, 'What are you going to eat now?'
"I will eat something, because I can't survive without food. But it is a concern for me what I will eat this afternoon or evening."
Mr Rahal said he'd barely eaten since the "revolting" experience, but managed a piece of bread with his medication this morning.
"It disturbed my sleep, honestly, I'm disturbed."
"I'm a 53-year-old person, I've never seen that on a plate in my whole life."
"The fact it was alive had made it worse," he said.
"If it was dead, it's a different story, [but] it's live. Dead is still a concern to me, but it's live."
He was disappointed a big supermarket such as Countdown would sell salad with a live creature in it.
"If I buy something from a flea market we can see something happening, but this one?"
Mr Rahal said it wasn't his intention to make a "fuss" but it was a matter of "moral responsibility".
"To me it's wrong," he said. "Something happened [that's] wrong, and I have to raise my voice."
Snap Fresh Foods, the company behind Krispkut, said it had been in touch with Countdown.
Snap Fresh Foods managing director John Wafer said Krispkut was a brand exclusive to Countdown.
"We did supply an extensive statement to Countdown so I can't comment at all."
US-based Golden State Foods bought Snap last year.
Countdown apologised for the incident.
"We have been in touch with the customer to apologise for what has happened and have also offered him a gift voucher for his inconvenience," said Steve Sexton, Countdown's merchandise manager for produce.
"The supplier has informed us that they go to great lengths to ensure their products are free from insects, including random sample inspections of the raw material, inspections of the trimmed material by their quality assurance team throughout the process, and washing the produce three times," he added.
"However, given this product is grown in an outdoor environment, occasionally something like this can happen."
