Can absorb people's energy and matter by stabbing them with the stinger on his tail

Cell's thick, muscular tail—a smooth, solid green appendage with black marks scattered across it—was more of a weapon than anything else. The Z Fighters still didn't know that it was the key to his absorption abilities; it had allowed him to absorb the entire population of Gingertown. The sharp, six-inch brown stinger on the end was now embedded in the prince's neck.

...

When no one moved, Cell continued his rant. "And now, Vegeta, allow me to put all that energy of yours to better use! Hahahahah!" Immediately he began to suck through his tail, attempting to drain not only Vegeta's energy but also his entire biological essence.

CRUNCH! Vegeta suddenly twisted, gripping Cell's tail with one powerful fist. The prince's strong fingers dug into the monster's flesh forcefully, breaking through skin and meat, until Cell was gasping in pain. Then, effortlessly, Vegeta lifted the stinger out from the back of his neck and turned.

"Oh, Cell. Did you really think you could defeat me so easily?" the deep, confident voice of the prince boomed. Vegeta twisted his neck from side to side, cracking it forcefully as he stretched.

With his left hand, the prince reached around and felt the spot on the back of his neck where Cell's stinger had pierced his flesh. How fortunate that Cell had struck the one point on his body that wasn't organic, the one place where Cell was incapable of draining any energy. Vegeta was dismayed at how narrowly he had escaped defeat…but he wasn't about to let Cell discover what was still a weakness.

- Bringer of Death Chapter 44

Suddenly, a new and sharper pain shot through his entire nervous system, piercing his consciousness. The agony reverberated through his body from his right leg. Looking down, he saw that Cell's tail had pierced his thigh. As 18 watched in horror, Cell began sucking the life out of Krillin, reducing his leg to nothing more than a shriveled ribbon of skin.

- Bringer of Death Chapter 51