@Graviity
Chapter 12 came out in Japan back in 2019 but it also came out in English over two weeks ago.
https://global.bookwalker.jp/de5a954807-5430-407f-8aec-c99a36a2f1c6/the-sorcerer-king-of-destruction-and-the-golem-of-the-barbarian-queen-vol-2/
The whole situation with this manga getting translated is so weird, after like a year from chapter 4 chapter 5 came out and then there was a drought again and I think it was cancelled at that point and then the last 3 chapters have been so weirdly released.
@Graviity I agree with @Duainfey. The "piko piko" on page 6 are likely onomatopoeic sound effects for Goltarou's ears flicking up and down sharply (out of happiness/excitement).
If it were from MC's patting, it would probably be "pon pon" (and similarly, if it were from MC's rubbing, it would probably be "nade nade").