I don't think any of these guys ever appeared in the comics, although I believe Chainsaw and Two-Head made it on the Incredible Hulk cartoon from the 90's. Still they all look really interesting (in the case of Mecha-Hulk, sheer awesomeness).
Chainsaw - from the Toybiz Incredible Hulk Outcasts series.
Leader-Hulk - from the Toybiz Incredible Hulk Outcasts series.
Two-Head - from the Toybiz Incredible Hulk Outcasts series.
Mecha Hulk - from the Toybiz Incredible Hulk Classics Series 2, had a hatch in the back for Gremlin to fit inside. A great Art Adams designed figure!