I believe you missed closing ) parentheses.
Code:
deadcheck {
  if ($stats($1,Stats,Chp) < 1) && ($stats($1,Status,Entered == Yes)[color:red])[/color] {
    var %zenny = $stats($2,Stats,Zenny)
    var %zenny.rand = $rand(11,21)
    inc %zenny %zenny.rand
    wini $2 Stats Zenny %zenny
    msg %DiGi 4 $+ $1 10was Destroyed by4 $2
    wini $1 Status Entered no
    wini $1 Status Atking no
    wini $1 Stats Chp 0
  }
} 


-Andy