YAY

It took me three times to beat them.

Chess.com wasn't careful with the names, because Boshi is claimed by Nintendo.

Star Plumber is something that you win by time out.

Scroll down from "Challenge", click on Custom. Set time to 1 minute. If you play correctly, Star Plumber will time out and you'll get an easy win.

Howser is more aggressive and I wouldn't recommend it on them.

Sometimes you have to stall him (Example: Nc6, Ng5, Nc6, Ng5) just so you can win on time. Sometimes I troll him by blundering my queen before he times out.

Also to help you: pre moves.

(Also, I think Star Plumber moves slower than most of the other bots.)

Keep trying. It's easier than beating them legitimately.

Same!