CREATE TABLE table_29623 ("Game" FLOAT, "December" FLOAT, "Opponent" CLOB, "Score" CLOB, "Location/Attendance" CLOB, "Record" CLOB, "Points" FLOAT)

Against what team did the Islanders have a 5-18-5 record?
SELECT "Opponent" FROM table_29623 WHERE "Record" = '5-18-5'
SELECT "Opponent" FROM "table_29623" WHERE "Record" = '5-18-5'