Siryn (X-Men Movies)

Siryn (Theresa Cassidy) is a mutant with the ability to produce a very loud, high pitched scream.

X-2: X-Men United
Siryn is seen as one of Storm's students at the Museum.

When HYDRA, under the control of Colonel William Stryker, attack the X-Mansion, she screams in horror at a sonic level before being tranquilized. She is eventually saved by Colossus.

X-Men: The Last Stand
She, along with other students, attended Professor X's funeral.

When the X-Mansion re-opens, she is seen giving Storm a hug before returning inside.