It is a common sight a lot of speculative terrestrial cephalopods and especially octopuses and not just that also is common see fictional works with creatures or characters with strong tentacles that can carry big objects.
Octopuses have great mobility under water, but all changes on the land as the gravity won't permit that the octopus could support its own weight to rise above the ground and not keep crawling on the ground, tentacles are not strong bones or exoskeletons.
So my principal comparison with the strongest tentacles are the elephant trunks, but even if these both are boneless muscular structures, are very different, for that my doubt is, what kind of adaptation should suffer an octopus to support its own weight with its tentacles? and even more is it possible that these tentacles will be stronger to hold biggest objects?
But now that was the case of the conventional cephalopod tentacles. Letting it aside, maybe a new tentacle-like structure that is not a real octopus tentacle for example a very segmented arm or column that could have the flexibility of a tentacle (something like the Dr. Octopus arms but in a biological way). But what I really I'm searching is something like the next images
So finally my principal requirements are:
- Capacity to be erect out of water.
- Enough force for hold at the least the half weight the creature which have this limbs.
- Flexibility
- Optional high movement speed.
(I've been searching about and asking in other sites and here are the given proposals: Reddit, Worldbuilding.SE, maybe you have other alternatives.)