BillR offers:

Came across this guy, Cameron Spires, who calls his strip Goat to Self. Most of his are borderline NSFW, or over the line, somewhat surrealistic, or just vague. Can’t figure this one out at all.

This editor posits that the key is that the dolphin (porpoise? beluga?) in the last panel is the defense lawyer, and the objection is to forcing self-incrimination. Mind you, I’m not sure that’s up to the defense lawyer — I think the witness has to invoke that themselves.