- Iron Man (Tony Stark) (Cameo)
- Mr. Fantastic (Reed Richards) (Cameo)
- Doctor Doom (Victor von Doom) (Cameo)
- The Leader (Samuel Sterns) (Cameo)
- Ego the Living Planet (Mentioned)
- Galactus (Mentioned)
- Pluto (Only in flashback)
- Abomination (Emil Blonsky) (Only in flashback)
- United States of America
- Russia (Only in flashback)
- Greece (Only in flashback)
With help from Betty Ross, Hulk allows himself to be turned back into Bruce Banner. Bruce Banner then struggles with the decision when Ronan the Accuser launches a Kree attack on Earth.
- This episode reveals that Hulk isn't capable to turn back to human even temporarily.
- The Hulk form seems to suppress Bruce Banner's scientific knowledge.
- Skaar calls Bruce Banner a "puny human", an expression from Hulk's other incarnations.