Stick insects..

Stick insects lose limbs sometimes from molting, and sometimes if it’s severe enough, they can suffocate while molting, killing them. Here’s a more detailed explanation:

Stick insects are sometimes found with one or more legs shorter than the others. This arises from the accidental loss of a leg which is later regenerated. A regenerated leg is always shorter than the normal leg, its actual length depending on the instar in which it was lost. For instance, if it is lost in the first instar it will be only slightly shorter than normal when the insect is full grown; if it is lost in the second or third instars it will be correspondingly so much shorter; a leg lost after the last moult cannot be regenerated, and remains as a stump. Legs lost are usually broken off at the coxal-trochanteral joint which covers over with a small black cap, underneath which the new leg gradually grows. As growth proceeds, the cap extends until a small loop or hook-like structure results, within which can be seen the perfect leg in miniature. This persists in this state until the next moult, and when the insect emerges from its old skin the loop has been replaced by a perfect though smaller leg.

It is not unusual for a leg to be lost during moulting, and in fact stick insects suffer a severe mortality rate during moulting as they sometimes fail to emerge properly from the old skin and become strangled, as it were, by it.

nzetc.org/tm/scholarly/tei-Bio05Tuat03-t1-body-d1.html