Emrick is a tiny sentient plant creature that appears in the fourth Thundercats (2011) episode, "Song of the Petalars". His species, the Petalars, live extremely short lives in comparison to other creatures. For a Petalar, a lifetime lasts a single day.
Lion-O and the Thundercats encountered the Petalars in the Briar Wood whilst trying to evade General Slithe and the Lizard army. Little Emrick quickly befriended Lion-O and told him about the Petalars and how they came to be lost in Briar Wood, and how they one day planned to return to their homeland of the Garden. Lion-O and the Thundercats decided to help the Petalars find the Cliff of Winds that would show them the way to the Garden and together they ventured through the woods, evading the predators that dwelled within and the advancing Lizard forces.
During their journey, Emrick was attacked and snatched up by a strange bird-like creature. He managed to free himself from the bird's grasp while Lion-O chased the creature down to find his friend. Mere minutes later, Lion-O found Emrick alive and well, but he had grown to a teenage state. That was when Lion-O became aware of the Petalars' brief lifespan.
As the Lizards close in on the Thundercats and the Petalars, Emrick decides to go and fight them. Lion-O manages to fight off the Lizards himself and Emrick gets mad and runs off. He reappears not long afterwards, having grown to an adult state.
An elderly Emrick moments before death
Lion-O and the others eventually find the Cliff of Winds (actually just a curled leaf) but there is no wind blowing to carry the Petalars away from the Briar Wood. However, the Lizards begin torching the forest and the fire creates an updraft that carries the Petalars away from the forest. Lion-O turns to Emrick and urges him to make his run to freedom, but Emrick has aged to an elderly state and is close to death. Lion-O feels heartbroken at the sight of his friend dying in his hands and apologises for not getting Emrick back to the Garden. Emrick tells Lion-O that it is not the destination itself but the journey that matters, and even though he lived such a short life compared to Lion-O, Emrick still lived his life to the fullest. Emrick then died peacefully in Lion-O's hands, his wilted body scattering apart on the wind.