arrival
arriviste
black sheep
blemish
burglar
busybody
buttinsky
comer
crasher
emigrant
encroacher
entrant
foreign body
foreign intruder
gate-crasher
gatecrasher
greenhorn
immigrant
imposer
impurity
in-migrant
incomer
infiltrator
interloper
invader
kibitzer
meddler
misfit
monkey wrench
mote
new arrival
new boy
newcomer
novus homo
obtruder
oddball
parvenu
recruit
rookie
settler
sliver
snooper
speck
splinter
squatter
stone
stowaway
stranger
tenderfoot
persona non grata
unwelcome person
alien
boarder
penetrator
prowler
pusher
sneak
stalker
thruster
unknown
unwelcome guest
intrude
intrusion
adventurer
adversary
assailant
assassin
attacker
attackers
caller
foe
invasion
killer
obstacle
outsider
predator
robber
spy
suitor
thief
visitor
wretch
Tudor
ruder