Update: ITTDGY in comments offers useful advice.
As any fule kno, life is all about mimicry, for predators and prey alike. Just look at the Mimic Elephant, which has evolved to resemble a wall, a pillar, a fan and a spear in order to evade detection by blind men. Also the corner of the room.
The boots-trap is a highly-specialised organism with many unique features which make it hard to classify. Some zoologists consider it to be related to nemertean worms (on the basis of its proboscis), but in the consensus opinion it is a form of coelenterate.