During the *Batman Beyond* series, there's the episode *[Terry's Friend Dates a Robot][1]* during which you can see Bruce Wayne actually training him to fight against robots, in a simulated fight against some of Bruce's old rogue gallery (The Riddler, Two Face, Killer Croc):

https://www.youtube.com/watch?v=ymkAIVIortk

Also, in episode *[Curse of the Kobra][2]*, Bruce also sends him into meeting with [Kairi Tanaga][3], whom Bruce knew from when he trained with [the same master][4] before becoming Batman, so that Terry could learn to fight more efficiently:

https://youtu.be/0NQGfr4xRcQ?t=163

It's more than likely that Bruce would continuously train him into becoming a better Batman, in order to increase his likelihood of staying alive.

It's questionable whether or not he became a master in martial arts like Bruce was, but we get a glimpse of how easily he took care of [Shriek][5] in the _[Justice League Unlimited][6]_ episode titled _[Epilogue][7]_, when he became a grown up man, long after the timeline of *Batman Beyond*:

https://youtu.be/Vd2qNR4phOU?t=56

On a more trivial note: there used to be a video on Youtube showcasing how Bruce (as Batman), always took out enemies coming from behind him by hitting them with his fist (which the video called his signature move). In a *Batman Beyond* episode, as Bruce was tending Terry's wound, the latter complained that he doesn't have eyes in his back.

The DCAU fandom does have a list of [the times Batman performs the offhand backhand][8] as described above. Two of them happened when:

- A henchman of Mr. Freeze attempts to sneak on him from behind in episode [Heart of Ice][9] from *[Batman: The Animated Series][10]*.

[![The aforementioned scene. Batman performs a offhand backhand punch using his left hand to knock out a henchman who tried to surprise him from behind.][11]][11]

- [Mercy Graves][12] attempted to shoot him from behind as he snuck on a sleeping Lex Luthor to interrogate him in the second part of episode *[World's Finest][13]* from _[Superman: The Animated Series][14]_

[![As Batman is interrogating Lex Luthor, he performs a offhand backhand punch to knock unconscious Mercy Graves who tried to shoot him from behind.][15]][15]

This was the scene I was referring where Terry told Bruce he doesn't have eyes in his back, when the latter asked him why he wasn't watching his back. It happened in episode *[Payback][16]* from *Batman Beyond*:

https://youtu.be/z7QHrrcPyGE?t=3

> Bruce: Why weren't you watching your back?  
> Terry: I was too busy watching my front!  Am I supposed to have eyes everywhere?  
> Bruce: Only if you want to live to a ripe old age.  
> Terry You don't make it sound too inviting.

Later on, in *[Batman_Beyond: Return of the Joker][17]* which happens after the events of *Batman Beyond*, Terry (as Batman) does it to a villain named [Ghoul][18] who tried to sneak up on him from behind, which means he probably learned the move from Bruce, or learned to watch his back as he was told.

https://youtu.be/rsSwSJ-rG_o?t=20

[![Batman (Terry) knocking out Ghoul as he was attempting to sneak up on him from behind.][19]][19]

And at the beginning of the final episode of the DCAU continuity, titled *Epilogue* from *Justice League Unlimited*, a grown up Terry also does it again, this time against a security guard approaching him from behind as he's sneaking into a highly secured home.

https://youtu.be/R8KIBm6BWTs?t=20


  [1]: https://dcau.fandom.com/wiki/Terry%27s_Friend_Dates_a_Robot
  [2]: https://dcau.fandom.com/wiki/Curse_of_the_Kobra
  [3]: https://dcau.fandom.com/wiki/Kairi_Tanaga
  [4]: https://dcau.fandom.com/wiki/Yoru
  [5]: https://dcau.fandom.com/wiki/Shriek
  [6]: https://dcau.fandom.com/wiki/Justice_League_Unlimited_(animated_series)
  [7]: https://dcau.fandom.com/wiki/Epilogue
  [8]: https://dcau.fandom.com/wiki/List_of_times_Batman_uses_the_offhand_backhand
  [9]: https://dcau.fandom.com/wiki/Heart_of_Ice
  [10]: https://dcau.fandom.com/wiki/Batman:_The_Animated_Series
  [11]: https://i.sstatic.net/B6uDnMzu.png
  [12]: https://dcau.fandom.com/wiki/Mercy_Graves
  [13]: https://dcau.fandom.com/wiki/World%27s_Finest,_Part_II
  [14]: https://dcau.fandom.com/wiki/Superman:_The_Animated_Series
  [15]: https://i.sstatic.net/oT6d3SxA.png
  [16]: https://dcau.fandom.com/wiki/Payback_(episode)
  [17]: https://dcau.fandom.com/wiki/Batman_Beyond:_Return_of_the_Joker
  [18]: https://dcau.fandom.com/wiki/Ghoul
  [19]: https://i.sstatic.net/YFga06x7.png