Almost everything we know of Jake's father comes from Jake's rants about what a bastard the old man was. While one can assume that Jake's recollections may be somewhat colored, evidence indicates that "Mad Dog" just wasn't a nice guy.

Jake's resentment toward his father stems from two main issues: his father's lack of caring and nurturing, and the fact that he sent Jake to military school. "Mad Dog" refused to give Jake a G.I. Joe, saying he didn't want his son playing with dolls. He was apparently very hard on Jake, continually pointing out how Jake was screwing up.

"Mad Dog's" wife Ruth seems to have had a better relationship with him, but even she has plenty of issues that she keeps hidden just under the surface. For instance, he gave her $50 per month as an "allowance" which she considered inadequate recognition for raising his children (this indicates that Jake has at least one sibling).

It is known that he had a razor phobia, and therefore presumably had a beard.

"Mad Dog" was dead before reaching his mid-forties, perhaps of a heart attack.

The quote above was from Jake, remembering something his father had once said. It is therefore uncertain whether Jake got it exactly right, or if his memory is colored by bitterness.