This page explains in detail the interactions between the Star Fox series and the Tekken series.
Tekken Tag Tournament 2 Wii U Edition[]
November 18, 2012
Star Fox
Tekken
The Wii U version of Tekken Tag Tournament 2 features exclusive costumes based on Nintendo characters for the fighters. There's a total of 12 different costumes, including one based on Fox McCloud from the Star Fox series (see here for other series). Worn by Baek, Dr. Boskonovitch, Hwoarang, Lee and Steve, it consists in Fox's clothes and helmet as well as his ears and tail. It was assigned to Steve likely because of his last name being Fox.
License[]
In an agreement between Nintendo and Bandai Namco, Nintendo-exclusive content was included in the game to create a double way marketing, with the game promoting the console and vice versa.