Oggy and the Cockroaches (1999)

S5E8 The Octopus Masters

Oggy discovers a mystical medallion in a sunken shipwreck and hands it over to Olivia. Once she dons the medallion, a magical octopus materializes, ready to fulfill her every command. However, the pesky cockroaches soon set their sights on the medallion as well, eager to claim its power for themselves.