The most common and most likely answer to this crossword clue is the 7 letter word INVADER
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More clues leading to the result INVADER
- Aggressor is popular villain
- One encroaches upon rocky ravine when touring Germany
- One carrying out raid, even without its initiator?
- One attacks popular Star Wars character
- Alien attacking popular Star Wars character
- Popular Star Wars character’s after alien attacker
- A driven out intruder
- Drive an unusual visitor
- Trespasser, driven off, seizing article
- In Star Wars villain, hostile alien
Buddy explains!

The straight part
We know that "Alien attacking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case alien attacking = invader.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does INVADER mean?
INVADER noun- One who invades a region
- An intruder (especially on someone's privacy)