A Texas thief stole nearly $2,000 worth of emergency medication from the wheelchair of a terminally ill boy at the State Fair — before a good Samaritan stepped in to help replace the life-saving meds.

Single mom Kayla Price, whose son Devin Cervantes, 3, has terminal brain cancer, said her purse containing two doses of medication used to stop his seizures and $1,500 in cash was stolen while she visited the Dallas fair with her children on Oct. 6.

“The potential of my son having a seizure and me not having that medication … it sucks,” Price told Fox 4 on Oct. 8. “I could lose everything because of someone’s careless act. It really hurts because I would do anything for my baby.”

Price had taken her children to the fair — a week before the annual event closed for the year — for a rare outing after Devin had been feeling particularly well.

However, Prices’ purse was stolen from her son’s wheelchair when she briefly turned her attention to her older son.

She said the prescription nasal spray inside her purse was vital to stopping Devin’s seizures, and insurance would not cover a replacement.

Price reported the theft to Dallas police and pleaded for the thief to return her belongings.

“I hope, I really wish you had it in your heart to return everything,” she told Fox 4.

“You don’t know the pain that you’re causing me or my kids who you’re hurting. Just give it all back.”

Devin is battling stage 4 terminal brain cancer and has been placed in hospice care.

His mom said he has endured six rounds of chemotherapy and 45 radiation treatments, but his tumor continued to grow.

Price has described her son as a cheerful boy who loves dancing, Spider-Man and SpongeBob SquarePants.

“Despite everything he’s going through, Devin is still the happiest little boy,” she wrote in a GoFundMe appeal.

Price’s nightmare escalated when Devin suffered a prolonged seizure on Oct. 9, leaving Price desperate to replace the medication, NBC 5 reported.

But help arrived when Dallas man Chris Bailey, who runs the Everybody Love Everybody Facebook group, heard about the theft and donated $2,000 to help the family cover the cost of the medicine.

“I sent her the money yesterday, and she immediately went to the pharmacy and filled it,” Bailey told the outlet.

“That medicine gave me a couple more days, a couple of more weeks, hopefully, and I am so glad,” Price added.

Bailey said he hoped to meet Devin and had another gift planned for the youngster.

“A little early Christmas surprise,” he told NBC 5.