This is not Purim Torah, but rather a thought experiment about Hilchos Shabbos.
Potentially, there are several Melachos that Bruce Banner violates in his transformation into the Hulk:
- Dyeing his skin, comparable to those who prohibit tanning on Shabbos
- Tearing his clothing
- Growing (comparable to growing out one's nails, which begin growing three days after being cut; see Mishnah Berurah 260:6)
- All of the destruction caused after his transformation; perhaps the transformation itself is forbidden in order to prevent damage from occurring after
The first two might be considered indirect (gerama), which might be entirely permissible, or direct but unwanted (pesik reisha d'lo nicha lei), for which there are certain leniencies.
The last two are entirely the purpose of the transformation, so at first glance it would seem that those should be forbidden entirely. However, it should be noted that, at least in most canons, the Hulk doesn't transform at will, but rather is tied to other stimuli, such as the time of day, or, more famously, his emotions. Therefore, perhaps it would depend on his intent: if Banner doesn't want to transform, getting angry would only be a pesik reisha d'lo nicha lei.
Is my reasoning correct? Would Banner's becoming angry on Shabbos be just a pesik reisha d'lo nicha lei at worst?