Edit: We have already freed them. We were worried that they were poisonous and something could happen to our dog. Thank you very much to all.
Venomous: it bites you, you die.
Poisonous: you bite it, you die.
Please don't eat the lizards, they just vibin', doin' lizard shit.
Dog's gonna be doggin'.
We were worried that they were poisonous and something could happen to our dog.
Definitely a type of wall/rock lizard. Hard to see their markings, maybe ready to molt? I don't think they're poisonous, and I also don't think there even are any poisonous lizards. Regardless, should release them. The only reason not to would be if you definitely know that they're an invasive species. Some of these types of lizards are endangered too, so.
Thank you, they are free now
Maybe a Lilford's Wall Lizard?
I'm not an expert, but I did some searching and it doesn't look like there are any venomous lizards in Spain. It's pretty rare for lizards to be problematic for humans, mostly they're just good pest control. I'd set the little guys free.