This mod was created primarily as an experiment. It adds a grab-pack with very well-developed mechanics.
Grab pack capabilities
1 - Activation of levers, doors, buttons and some other blocks at a distance.
2 - Attracting mobs. To do this, you need to shoot at the mob and sit down while returning your hand. The larger the mob, the longer it will take.
3 - Attraction and swing. If you shoot a block of mucus or honey with your hand, you will be able to pull yourself up to it, and if you sit down, you will swing like on a bungee. This is the most interesting mechanic.
For this mod you need Geckolib!
The hands are just entities, and there is a particle beam (rope) between them and the player. You can find a tutorial on making such beams on the Kyoukster channel. Find it on YouTube. To make it stick to blocks, you can simply check if there is a solid block around or not, and if so, just stop the hand speed. I tried to tell you as briefly and in detail as I can
More Minecraft Mods
Would you be willing to open up a bit on how you did this? I've been working on my own Poppy mod and the red and blue hands have been a huge roadblock for me.