Here are the list of characters that has an account and their names:

Tintin ~ @CuriousTintin (me)
Chang Chong-Chen ~ @GoofyChineseBoy
Captain Haddock ~ @BBlueBarnacles
Professor Calculus ~ @notactingagoat
Abdullah ~ @PrincePrankster
Sakharine (movie version) ~ @IvanSakharine
Piotr Skut ~ @PiotrSkut
The Yeti (the yeti from "Tintin in Tibet") ~ @GentleYeti

Open spots for characters (wanted)

Nestor
Thompson
Thomson
Bianca Castafiore
General Alcazar
Rastapopolous
and Allan

Please contact @CuriousTintin or comment below for more info

Tintin married a woman named Martine Vandezande. They had 4 children who were all named after Tintin's friends. The kids were named Bianca Irma Tin, Cuthbert Zorrino Tin, Miarka Martine Tin and Ben Chang Tin.

Captain Haddock married Bianca Castafiore's sister Ada.

Cuthbert Calculus married Bianca Castafiore 1 year before Tintin and Martine married.

Snowy had 4 puppies named Misty, Chilly, Sunny and Rainy.

Zorrino married a Belgian woman named Mary Peeters and had two daughters named Jane and Charlotte.

Chang had two daughters named Shu and Zhen. Shu and Zhen were twins and they were 1 day younger than Tintin's youngest child Cuthbert. Cuthbert and Zhen fell in love and eventually married. They had 3 daughters and a son named Penelope "Penny", Rose, Phoebe and James.

Tintin became the most famous reporter in history.

1: Tintin
2: Snowy
3: Captain Haddock
4: Thompson and Thomson
5: Professor Calculus
6: Abdullah
7: Enaddine Akass
8: General Alcazar
9: Professor Hector Alembick
10: Alonso and Ramon
11: Barnaby
12: Mr Baxter
13: Big Chief Keen-Eyed Mole
14: Bill
15: The Bird Brothers
16: Mr Bohlwinkel
17: Mr Bolt
18: Colonel Boris
19: Borschtisov
20: Rascar Capac
21: Al Capone
22: Chang
23: Captain Chester
24: Dawson
25: Lieutenant Doctor
26: Corporal Diaz
27: Didi
28: The Director of Kidnap Inc.
29: Emir Ben Kalish Ezab
30: The Fakir
31: Henri Fourcart
32: Mr Gibbons
33: The Grand Abbot
34: Sir Francis Haddock
35: Huascar
36: Irma
37: Ivan
38: Colonel Jorgen
39: Mik Kanrokitoff
40: Dr Krollspell
41: Lazlo Carreidas
42: Bianca Castafiore
43: Bunji Kuraki