VoxeLibre/mods/ENTITIES/mcl_mobs/api/mob_functions/interaction.lua

-- Code to execute before custom on_rightclick handling
local on_rightclick_prefix = function(self, clicker)
	local item = clicker:get_wielded_item()

	-- Name mob with nametag
	if not self.ignores_nametag and item:get_name() == "mcl_mobs:nametag" then

		local tag = item:get_meta():get_string("name")
		if tag ~= "" then
			if string.len(tag) > MAX_MOB_NAME_LENGTH then
				tag = string.sub(tag, 1, MAX_MOB_NAME_LENGTH)
			end
			self.nametag = tag

			update_tag(self)

			if not mobs.is_creative(clicker:get_player_name()) then
				item:take_item()
				clicker:set_wielded_item(item)
			end
			return true
		end

	end
	return false
end

mobs.create_mob_on_rightclick = function(on_rightclick)
	return function(self, clicker)
		local stop = on_rightclick_prefix(self, clicker)
		if (not stop) and (on_rightclick) then
			on_rightclick(self, clicker)
		end
	end
end

mobs.feed_tame = function(self)
    return nil
end