Banjo Kazooie in Super Mario 64: Whomp's Fortress - N64 Squid

Whomp's Fortress is a Nintendo 64 hack of Banjo Kazooie in which you can play Super Mario 64's second level as well as Super Mario Bros' level 1-2.

Banjo-Kazooie in Super Mario 64 (Nintendo 64)

Super Mario 64 vs Banjo-Kazooie - General Discussion - Giant Bomb

SMG4: AREA 64, The SMG4/GLITCH Wiki

Banjo Kazooie in Super Mario 64: Whomp's Fortress - N64 Squid

Banjo Kazooie in Super Mario 64: Whomp's Fortress - N64 Squid

Mario, DK, Banjo and Kazooie(N64 models) by Banjo2015 on DeviantArt

Banjo Kazooie in Super Mario 64: Whomp's Fortress - N64 Squid

Banjo-Kazooie in Super Mario 64 (Real N64 Capture)

Mario 64 x Banjo Kazooie - Spiral Mountain Preview