What does 馬になる mean


I tried to figure out what this could mean, is it word play? I couldn't find
any info.

[![enter image description
here](https://i.stack.imgur.com/jAoXq.png)](https://i.stack.imgur.com/jAoXq.png)




This is a catchphrase of [this
YouTuber](https://dic.nicovideo.jp/a/%E5%A4%A7%E8%9B%87%E4%B8%B8%E3%81%AE%E4%BA%BA).
He became famous around 2019 for his videos in which he cooks while imitating
the voices of anime characters and using a lot of wordplay
([オヤジギャグ](https://blog.gaijinpot.com/oyaji-gyagu-a-guide-to-japanese-dad-
jokes/)) including うますぎて馬になる (which of course is a wordplay around 旨い "yummy"
and 馬 "horse").

> ### ウマすぎてウマになる（ウマすぎてウマになった）
>
>
> 肴が美味かったときの定番セリフ。後ろに絵文字が付くことがあるが、だいたい馬ではない（、…）。「優勝」と同じく、オタク構文の「そりすぎてソリになったｗ」が出所と思われる。

Here's an example of his video (the phrase in question is near the end of the
video): [【牛タンのシチュー】自分を大蛇丸と信じて止まない一般男性が優勝する動画です。](https://youtu.be/IAeQTbnX4tc)

