wget command to download a file and save as a different filename

Use the -O file option.

E.g.

wget google.com
...
16:07:52 (538.47 MB/s) - `index.html' saved [10728]

vs.

wget -O foo.html google.com
...
16:08:00 (1.57 MB/s) - `foo.html' saved [10728]