def list = ['My_name_is_Jack', 'My_name_is_Rock', 'My_name_is_Sunn']
def getName = { s -> s.substring(s.lastIndexOf('_')+1, s.size()) }
println list.collect{getName it}
//With replace
def getNameWithReplace = { s -> s.replace('My_name_is_', '') }
println list.collect{getNameWithReplace it}
ZGVmIGxpc3QgPSBbJ015X25hbWVfaXNfSmFjaycsICdNeV9uYW1lX2lzX1JvY2snLCAnTXlfbmFtZV9pc19TdW5uJ10KZGVmIGdldE5hbWUgPSB7IHMgLT4gcy5zdWJzdHJpbmcocy5sYXN0SW5kZXhPZignXycpKzEsIHMuc2l6ZSgpKSB9CnByaW50bG4gbGlzdC5jb2xsZWN0e2dldE5hbWUgaXR9CgovL1dpdGggcmVwbGFjZQpkZWYgZ2V0TmFtZVdpdGhSZXBsYWNlID0geyBzIC0+IHMucmVwbGFjZSgnTXlfbmFtZV9pc18nLCAnJykgfQpwcmludGxuIGxpc3QuY29sbGVjdHtnZXROYW1lV2l0aFJlcGxhY2UgaXR9