What is this on my pear? :)

[MarkHackwell]

What is this on my pear? is it a sucker and should i cut it off?

[boundtothesoil]

is it a sucker and should i cut it off?

In my opinion, the thickest upright with the short horizontal stubs looks like the tree's proper trunk (i.e. the variety you are trying to grow). All the thinner ones are suckers, most likely arising from the rootstock onto which your variety was grafted. I'd cut them all off with a slightly diagonal cut a couple of millimeters from the base now if it were my tree, as they will just divert nutrients and water away from the part of the tree you are trying to grow and will inevitably grow faster as a result!

However, I'd wait to see if others disagree with this view

[FB.]

They are suckers - a common problem with dwarfing and semi-dwarfing rootstocks because of the impaired sapflow at the graft (due to partial incompatibility) which can cause the roots to vent out their pent-up energy from below the graft.
Suckers can occasionally be a sign of a sick or dead above-ground portion, so the roots vent out their sap by growing a new trunk (which will not produce the same fruit as the above-ground part) - suckers will not produce the fruit you want (most pear rootstocks are grown from quince trees) and suckers will draw energy/compete with the tree and fruit which you do want.
Suckers also give diseases two chances to attack the tree - even if the grafted part is disease-resistant the rootstock shoots and leaves may not be; allowing diseases to enter and maybe even kill the tree.

Cut suckers off flush to the trunk as soon as they are seen during the growing season - zero tolerance unless you intend to harvest them during winter to produce more rootstocks for grafting new trees. Two-year-old Quince cuttings with lumpy stems (burrknots) taken when the leaves are yellow will usually root after several months of winter and can be grafted the next winter.

Unwanted above-ground suckers are best removed while small to prevent them building strength and establishing a strong sapflow from the roots which can cause them to keep coming back from nearby areas of bark even when cut back flush to the trunk.

If suckers emerge from the ground use a trowel to carefully dig down and remove right back to the root they came from - even removing a piece of root if necessary (but don't remove any roots while the tree is in full leaf or it may not be able to draw water!).
If any bit of the sucker remains, it will often fight back with several shoots in place of the original one.