If you really dislike it, carry out the following:
Start Update Manager.
From the Edit menu, select Preferences. Tick Only show a tray icon when updates are available or in case of errors.
Optionally, un-tick Show a warning if system snapshots are not set up. Alternatively, take a system snapshot.
The icon should disappear. The ugly icon will reappear if there are any updates and hopefully frighten you into keeping your system fully updated ;-)