Super Mega Cannon Sigma
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Super Mega Cannon Sigma (スーパー メガ キャノン シグマ, Sūpā Mega Kyanon Shiguma; FUNimation "Sigma Force Cannon") was the Fusion of the Machine Mutants Nezi, Ribet, and Bizu. With the death of Natt, the other Mega Cannon Sigma members fused to become Super Mega Cannon Sigma when they tried to defeat Son Goku even though they seemed to have Goku worried. This was because he was holding back and trying to figure out their moves and fighting style like they had done to him. He then went to his full power and defeated them effortlessly.
He is named Sūpā Σ (スーパー Σ, Sūpā Σ) in Miracle Battle Carddass Dragon Ball Kai.
He is named Sūpā Σ I (スーパー Σ I, Sūpā Σ I) in his first form and Sūpā Σ II (スーパー Σ II, Sūpā Σ II) in his second form in Dragon Ball Carddass Hondan.