each role requires a mascot; whom would you nominate?
Adc:
Sup:
Mid:
Jg:
Top: 
Adc:
Sup:
Mid:
Jg:
Top: 
adc -
- glory hogs with an inflated ego
sup -
- A role made for traumatized sadists that are unable to speak
mid -
- "ALL WILL BEHOLD"
jg -
- no friends
top -
- it's so lonely up here
Top:
Jungle:
Mid:
AD Carry:
Support: 

Shit this is hard
ADC:
Because we all know that ADC's are just douchebags.
SUPP:
Do I have to list a reason?
MID:
Either really good or really bad.
JG:
I like being alone
Top:
BUSHES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
adc -
http://vignette2.wikia.nocookie.net/leagueoflegends/images/4/48/TahmKench.tauntCaitlyn01.ogg/revision/latest?cb=20150624151334
mid -
http://vignette2.wikia.nocookie.net/leagueoflegends/images/2/27/TahmKench.tauntJayce01.ogg/revision/latest?cb=20150624151513
top -
http://vignette1.wikia.nocookie.net/leagueoflegends/images/d/d8/TahmKench.tauntNasus01.ogg/revision/latest?cb=20150624151549
jung -
http://vignette4.wikia.nocookie.net/leagueoflegends/images/a/ae/TahmKench.tauntRenekton01.ogg/revision/latest?cb=20150624151550
sup -
http://vignette1.wikia.nocookie.net/leagueoflegends/images/d/da/Lux.move6.ogg/revision/latest?cb=20121120020651
Top:
Jg:
Mid:
Sup:
Adc: 
They aren't really getting played right now, so might as well give them something to do for fun.
: Stereotypical toxic top lane
: Stereotypical toxic mid lane
: Stereotypical toxic jungle
: Stereotypical toxic adc
: Stereotypical support
Mid
Top
Jungle
Adc
Support
/
Top
Jungle
Mid
Sup
Adc 
Bonus league mascot
(a dead one)

Agreed except annie mid. She is really more of a sup when played at all. Ahri zed or yas are the mids I think of.
Annie definitely isn't mid since she's a flex pick.
is definitely the flagship mid laner. She's been mentioned by rioters as the bar for mid lane balance, she's seen competitive play, and embodies the Mage culture of mid lane (burst dmg, some CC, some utility).
It could be a few other mages though, as long as it isn't an AD mid laner. Reason being is those are a counter, a response, to the mages. Thus they don't identify the mid lane's identity, they exist because of it. Not a good rep.
You also have to think beyond the present meta. Picking whats popular now just shows your newness. A mascot should rep past, present, and future.