A USophant is similar to a sicophant. However instead of phanting sic a USophant phants the United States of America.
A USophant views America like a kid pressing his nose against the toy shop window.
Yankophile can also be used to desricbe a USophant.
These people sometimes affect a "mid-Atlantic" accent and often religously download TV direct from American Networks via the interwebs, disparaging their home nations cultural output in favour of Hollywood et al is another common trait.
Another common trait is obesity, which can be used to comedic effect. Refer to these people as USaphants.
"You know like elephants* they are huge, USA loving gits"
Many USophants also create American sounding nicknames like DayZ (instead of Daisy), Cadillac or Hilary Clinton.
*Not actually known if real Elephants love the USA.
"See that Dave, he's a real USophant"
Meaning Dave loves America so much he would walk 30 miles through flaming shit to chat with somone who'd actually been to America.