The rubber ducky is a popular toy for kids who enjoy playing with it during bath time or in the swimming pool.

For the staff of the New England Aquarium (NEA) in Boston, Massachusetts, USA, the yellow duckling is more than a toy. They use it to train an aquarium resident named Reggae.

The 33-year-old Atlantic harbor seal plays fetch with the rubber duck in a 42,000-gallon outdoor tank to practice his memory, problem-solving and focus, ABC News reported.

Reggae also strengthens relationships with NEA trainers when he plays catch with them.

The seal drew attention on social media after the aquarium posted a video of him tightly hugging the duck while floating on his belly and tucking it under his flipper, appearing to pat its head while sitting on a rock, according to ABC News.

Meanwhile, a baby macaque at the Ichikawa City Zoo (ICZ) in Chiba Prefecture, Japan, has its own special companion.

The six-month-old Punch was orphaned when he was born in July, as his mother was not interested in nursing the monkey. Zoo staff looked for a suitable “mother” for Punch and found one.

Scenes of Punch dragging “his mother,” twice his size, and running back and forth around Monkey Mountain became popular not only among visitors but also on social media, The Japan News reported.

The “mom,” an orangutan stuffed toy, came from IKEA Japan. When officials of the furniture store saw the video of Punch lying beside the stuffed toy, they were touched.

IKEA Japan in Funabashi, Chiba Prefecture, donated 33 of its stuffed animals to Ichikawa City, which runs the zoo, on 17 February. The zoo plans to use them as spare stuffed animals.