This is a completely normal grenade and will damage any player character in the blast radius, not just the Vault Hunter who actually used the slot machine.
Or, rarely, purple weapon and sometimes the chance for character or vehicle skins.
Two bells with any non-psycho mask at the end: One to Three piles of Cash.Any 2 matching with bell at the end: One to Three piles of Cash.First and second symbols different (regardless of 3rd): No reward.(For 'Pre-Sequel', subtitute 'Moonstones' for 'Eridium Bars'.) Borderlands 2 and the Pre-Sequel Known combinations and rewards