Nico

Nico is an old friend of Vinnie's from Russia. He doesn't appear much in the series but he is as useful when he does show up. He is a (retired?) assassin(verification needed) like Vinnie.

Sift Heads 4
Nico asks a favour of Vinnie to kill a target for him and make it look like he did it by "making his neck stick out".

Sift Heads World- Act 4
Nico makes an appearence in World Act 4. He lets them use his hanger as a safehouse in Russia while Vinnie and his team look for Shorty's sister Claire. He also provides a jeep for the team to use and, after finding parts to repair it, his helicopter is used to find Claire in a Human Trafficking Organisation hideout.

Sift Heads Reborn - Takedown
While in Sift Heads Reborn Career mode, his appearance in chapter 4 (Sift Heads World Act 4) remains the same as in the original game. However in Takedown mode, if the player runs out of ammo during a contract, they will call in Nico to drop an emergency package of ammo from his helicopter for an increased cost.