Dr Wendell is Pete's dad.
So, for this theory, we're going to ignore all supplemental material, and only focus on what we learn in game.- Pete never gives his last name. All the other kids give their last name as part of their Greeting. We learn their names are "Alley Hoops", "Maxwell Smalls", "Willow Branch", and "Peter, but my friends call me Pete". The game is disguising Pete's last name.
- Dr Wendell mentions having a son, and wanting to entertain him with one of his experiments in one of his audio logs
- The house appears to belong to Dr Wendell, based on how much access he had to it, to have built all his tiny labs there. If so, the Not-Dungeons and Dragons game on the park bench must be his as well, or his son's. One of Pete's intro lines implies he likes to play the Not-Dungeons and Dragons game. If Dr Wendell's son was one of the protagonists, Pete is the most likely candidate.
- Dr Wendell engineered the potentially lethally horrible tasting "Muscle Sprouts" mostly out of his larder's abundance of Brussel Sprouts to use as samples. Pete will often compare poor quality foraging unfavorably to "My father's Brussel sprouts".
Individually none of these makes a convincing case, but taken in aggregate...
If you take supplemental materials as canon, however, the Steam cards reveal that Pete's full name is Pete Boggs. Dr Wendell Tully doesn't share this name.
